- | Enhance stability of caching the schema information when there are a massive number of tables (experimental) |
+ Enhance the stability of caching the schema information when there is a massive number of tables (experimental) |
SaaS companies using TiDB as the system of record for their multi-tenant applications often need to store a substantial number of tables. In previous versions, handling table counts in the order of a million or more was feasible, but it had the potential to degrade the overall user experience. TiDB v8.0.0 improves the situation with the following enhancements:
- Introduce a new schema information caching system, incorporating a lazy-loading Least Recently Used (LRU) cache for table metadata and more efficiently managing schema version changes.
@@ -47,7 +47,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
| DB Operations and Observability |
Support monitoring index usage statistics |
- TiDB v8.0.0 introduces the INFORMATION_SCHEMA.TIDB_INDEX_USAGE table and the sys.schema_unused_index view to provide usage statistics of indexes. This feature helps you assess the importance of all indexes and optimize the index design. |
+ Proper index design is a crucial prerequisite for improving database performance. TiDB v8.0.0 introduces the INFORMATION_SCHEMA.TIDB_INDEX_USAGE table and the sys.schema_unused_index view to provide usage statistics of indexes. This feature helps you assess the efficiency of indexes in the database and optimize the index design. |
| Data Migration |
@@ -65,7 +65,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### Scalability
-- PD supports the microservice mode (experimental) [#5766](https://github.com/tikv/pd/issues/5766) @[binshi-bing](https://github.com/binshi-bing) **tw@qiancai**
+- PD supports the microservice mode (experimental) [#5766](https://github.com/tikv/pd/issues/5766) @[binshi-bing](https://github.com/binshi-bing)
Starting from v8.0.0, PD supports the microservice mode. This mode splits the timestamp allocation and cluster scheduling functions of PD into separate microservices that can be deployed independently, thereby enhancing performance scalability for PD and addressing performance bottlenecks of PD in large-scale clusters.
@@ -78,47 +78,47 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
For more information, see [documentation](/pd-microservices.md).
-* Enhance the usability of the Titan engine [#16245](https://github.com/tikv/tikv/issues/16245) @[Connor1996](https://github.com/Connor1996) **tw@qiancai**
+* Enhance the usability of the Titan engine [#16245](https://github.com/tikv/tikv/issues/16245) @[Connor1996](https://github.com/Connor1996)
- - Enable the shared cache for Titan blob files and RocksDB block files by default ([`shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache-tidb-introduced-in-v800) defaults to `true`), eliminating the need to configure [`blob-cache-size`](/tikv-configuration-file.md#blob-cache-size) separately.
+ - Enable the shared cache for Titan blob files and RocksDB block files by default ([`shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache-new-in-v800) defaults to `true`), eliminating the need to configure [`blob-cache-size`](/tikv-configuration-file.md#blob-cache-size) separately.
- Support dynamically modifying [`min-blob-size`](/tikv-configuration-file.md#min-blob-size), [`blob-file-compression`](/tikv-configuration-file.md#blob-file-compression), and [`discardable-ratio`](/tikv-configuration-file.md#min-blob-size) to improve performance and flexibility when using the Titan engine.
For more information, see [documentation](/storage-engine/titan-configuration.md).
### Performance
-* BR improves snapshot restore speed (GA) [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer) @[Leavrth](https://github.com/Leavrth) **tw@qiancai**
+* BR improves snapshot restore speed (GA) [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer) @[Leavrth](https://github.com/Leavrth)
- Starting from TiDB v8.0.0, BR improves the snapshot restore speed significantly by implementing various optimizations such as adopting the coarse-grained Region scattering algorithm, creating databases and tables in batches, reducing the mutual impact between SST file downloads and ingest operations, and accelerating the restore of table statistics. According to test results from real-world cases, the data restore speed of a single TiKV node stabilizes at 1.2 GB/s, and 100 TiB of data can be restored within one hour. In TiDB v8.0.0, this improvement feature is now generally available (GA) and enabled by default.
+ Starting from TiDB v8.0.0, the acceleration of snapshot restore speed is now generally available (GA) and enabled by default. BR improves the snapshot restore speed significantly by implementing various optimizations such as adopting the coarse-grained Region scattering algorithm, creating databases and tables in batches, reducing the mutual impact between SST file downloads and ingest operations, and accelerating the restore of table statistics. According to test results from real-world cases, the data restore speed of a single TiKV node stabilizes at 1.2 GiB/s, and 100 TiB of data can be restored within one hour.
- This means that even in high-load environments, BR can fully utilize the resources of each TiKV node, significantly reducing database restore time, enhancing the availability and reliability of databases, and reducing downtime and business losses caused by data loss or system failures. Note that the increase in restore speed is attributed to the parallel execution of a large number of goroutines, which can result in significant memory consumption, especially when there are many tables or Regions. It is recommended to use machines with higher memory capacity to run the BR client. If the memory capacity of the machine is limited, it is recommended to use a finer-grained Region scattering algorithm.
+ This means that even in high-load environments, BR can fully utilize the resources of each TiKV node, significantly reducing database restore time, enhancing the availability and reliability of databases, and reducing downtime and business losses caused by data loss or system failures. Note that the increase in restore speed is attributed to the parallel execution of a large number of goroutines, which can result in significant memory consumption, especially when there are many tables or Regions. It is recommended to use machines with higher memory capacity to run the BR client. If the memory capacity of the machine is limited, it is recommended to use a finer-grained Region scattering algorithm. In addition, because the coarse-grained Region scattering algorithm might consume a significant amount of external storage bandwidth, you need to avoid any impact on other applications due to insufficient external bandwidth.
For more information, see [documentation](/br/br-snapshot-guide.md#restore-cluster-snapshots).
-* Support pushing down the following functions to TiFlash [#50975](https://github.com/pingcap/tidb/issues/50975) [#50485](https://github.com/pingcap/tidb/issues/50485) @[yibin87](https://github.com/yibin87) @[windtalker](https://github.com/windtalker) **tw@Oreoxmt**
+* Support pushing down the following functions to TiFlash [#50975](https://github.com/pingcap/tidb/issues/50975) [#50485](https://github.com/pingcap/tidb/issues/50485) @[yibin87](https://github.com/yibin87) @[windtalker](https://github.com/windtalker)
* `CAST(DECIMAL AS DOUBLE)`
* `POWER()`
For more information, see [documentation](/tiflash/tiflash-supported-pushdown-calculations.md).
-* The concurrent HashAgg algorithm of TiDB supports disk spill (experimental) [#35637](https://github.com/pingcap/tidb/issues/35637) @[xzhangxian1008](https://github.com/xzhangxian1008) **tw@qiancai**
+* The concurrent HashAgg algorithm of TiDB supports disk spill (experimental) [#35637](https://github.com/pingcap/tidb/issues/35637) @[xzhangxian1008](https://github.com/xzhangxian1008)
In earlier versions of TiDB, the concurrency algorithm of the HashAgg operator does not support disk spill. If the execution plan of a SQL statement contains the concurrent HashAgg operator, all the data for that SQL statement can only be processed in memory. Consequently, TiDB has to process a large amount of data in memory. When the data size exceeds the memory limit, TiDB can only choose the non-concurrent algorithm, which does not leverage concurrency for performance improvement.
- In v8.0.0, the concurrent HashAgg algorithm of TiDB supports disk spill. Under any concurrent conditions, the HashAgg operator can automatically trigger data spill based on memory usage, thus balancing performance and data throughput. Currently, as an experimental feature, TiDB introduces the `tidb_enable_concurrent_hashagg_spill` variable to control whether to enable the concurrent HashAgg algorithm that supports disk spill. When this variable is `ON`, it means enabled. This variable will be deprecated when the feature is generally available in a future release.
+ In v8.0.0, the concurrent HashAgg algorithm of TiDB supports disk spill. Under any concurrent conditions, the HashAgg operator can automatically trigger data spill based on memory usage, thus balancing performance and data throughput. Currently, as an experimental feature, TiDB introduces the `tidb_enable_concurrent_hashagg_spill` variable to control whether to enable the concurrent HashAgg algorithm that supports disk spill. When this variable is `ON`, it means enabled. This variable will be deprecated after the feature is generally available in a future release.
- For more information, see [documentation](/system-variables.md#tidb_enable_concurrent_hashagg_spill-new-in-v760).
+ For more information, see [documentation](/system-variables.md#tidb_enable_concurrent_hashagg_spill-new-in-v800).
-* Introduce the priority queue for automatic statistics update [#50132](https://github.com/pingcap/tidb/issues/50132) @[hi-rustin](https://github.com/hi-rustin) **tw@hfxsd**
+* Introduce the priority queue for automatic statistics collection [#50132](https://github.com/pingcap/tidb/issues/50132) @[hi-rustin](https://github.com/hi-rustin)
- Maintaining optimizer statistics up-to-date is the key to stabilizing database performance. Most users rely on the [automatic statistics update](/statistics.md#automatic-update) provided by TiDB to keep statistics up-to-date. Automatic statistics update polls the status of statistics for all objects, and adds objects with insufficient health to a queue for individual collection and update. In previous versions, the collection order is random, which could result in longer waits for more worthy objects to be updated, causing potential database performance regressions.
+ Maintaining optimizer statistics up-to-date is the key to stabilizing database performance. Most users rely on the [automatic statistics collection](/statistics.md#automatic-update) provided by TiDB to collect the latest statistics. Automatic statistics collection checks the status of statistics for all objects, and adds unhealthy objects to a queue for sequential collections. In previous versions, the order is random, which could result in excessive waits for more worthy candidates to be updated, causing potential performance regressions.
Starting from v8.0.0, automatic statistics update dynamically sets priorities for objects in combination with a variety of conditions to ensure that more valuable objects for collection are processed first, such as newly created indexes and partitioned tables with partition changes. Additionally, TiDB prioritizes tables with lower health scores, placing them at the front of the queue. This enhancement improves the reasonableness of the collection order, and reduces performance problems caused by outdated statistics, therefore improving database stability.
-
+
For more information, see [documentation](/system-variables.md#tidb_enable_auto_analyze_priority_queue-new-in-v800).
-* Remove some limitations on execution plan cache [#49161](https://github.com/pingcap/tidb/pull/49161) @[mjonss](https://github.com/mjonss) @[qw4990](https://github.com/qw4990) **tw@hfxsd**
+* Remove some limitations on execution plan cache [#49161](https://github.com/pingcap/tidb/pull/49161) @[mjonss](https://github.com/mjonss) @[qw4990](https://github.com/qw4990)
TiDB supports [execution plan cache](/sql-prepared-plan-cache.md), which can effectively reduce the processing latency of transaction-intensive systems and is important for improving performance. In v8.0.0, TiDB removes several limitations on execution plan cache. Execution plans with the following contents can be cached:
@@ -129,7 +129,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
For more information, see [documentation](/sql-prepared-plan-cache.md).
-* Optimizer enhances support for multi-valued indexes [#47759](https://github.com/pingcap/tidb/issues/47759) [#46539](https://github.com/pingcap/tidb/issues/46539) @[Arenatlx](https://github.com/Arenatlx) @[time-and-fate](https://github.com/time-and-fate) **tw@hfxsd**
+* Optimizer enhances support for multi-valued indexes [#47759](https://github.com/pingcap/tidb/issues/47759) [#46539](https://github.com/pingcap/tidb/issues/46539) @[Arenatlx](https://github.com/Arenatlx) @[time-and-fate](https://github.com/time-and-fate)
TiDB v6.6.0 introduces [multi-value indexes](/sql-statements/sql-statement-create-index.md#multi-valued-indexes) to improve query performance for JSON data types. In v8.0.0, the optimizer enhances its support for multi-valued indexes and can correctly identify and utilize them to optimize queries in complex scenarios.
@@ -137,8 +137,8 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
* When using `OR` to connect multiple `member of` conditions, the optimizer can match an effective index partial path for each DNF item (a `member of` condition) and combine these paths using Union to form an `Index Merge`. This achieves more efficient condition filtering and data querying.
For more information, see [documentation](/sql-statements/sql-statement-create-index.md#multi-valued-indexes).
-
-* Support configuring the update interval for low-precision TSO [#51081](https://github.com/pingcap/tidb/issues/51081) @[Tema](https://github.com/Tema) **tw@hfxsd**
+
+* Support configuring the update interval for low-precision TSO [#51081](https://github.com/pingcap/tidb/issues/51081) @[Tema](https://github.com/Tema)
The [low-precision TSO feature](/system-variables.md#tidb_low_resolution_tso) in TiDB uses regularly updated TSO as the transaction timestamp. In scenarios where reading outdated data is acceptable, this feature reduces the overhead of obtaining TSO for small read-only transactions by sacrificing real-time performance and improves the ability of high-concurrency reads.
@@ -148,20 +148,20 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### Reliability
-* Support caching required schema information according to the LRU algorithm to reduce memory consumption on the TiDB server (experimental) [#50959](https://github.com/pingcap/tidb/issues/50959) @[gmhdbjd](https://github.com/gmhdbjd) **tw@hfxsd**
+* Support caching required schema information according to the LRU algorithm to reduce memory consumption on the TiDB server (experimental) [#50959](https://github.com/pingcap/tidb/issues/50959) @[gmhdbjd](https://github.com/gmhdbjd)
+
+ Before v8.0.0, each TiDB node caches the schema information of all tables. In scenarios with hundreds of thousands of tables, just caching these table schemas could consume a significant amount of memory.
- Before v8.0.0, each TiDB node caches the schema information of all tables. In scenarios with hundreds of thousands of tables, just caching these table schemas could consume a significant amount of memory.
-
Starting from v8.0.0, TiDB introduces the system variable [`tidb_schema_cache_size`](/system-variables.md#tidb_schema_cache_size-new-in-v800), which enables you to set an upper limit for caching schema information, thereby preventing excessive memory usage. When you enable this feature, TiDB uses the Least Recently Used (LRU) algorithm to cache the required tables, effectively reducing the memory consumed by the schema information.
For more information, see [documentation](/system-variables.md#tidb_schema_cache_size-new-in-v800).
### Availability
-* The proxy component TiProxy becomes generally available (GA) [#413](https://github.com/pingcap/tiproxy/issues/413) @[djshow832](https://github.com/djshow832) @[xhebox](https://github.com/xhebox) **tw@Oreoxmt**
+* The proxy component TiProxy becomes generally available (GA) [#413](https://github.com/pingcap/tiproxy/issues/413) @[djshow832](https://github.com/djshow832) @[xhebox](https://github.com/xhebox)
TiDB v7.6.0 introduces the proxy component TiProxy as an experimental feature. TiProxy is the official proxy component of TiDB, located between the client and TiDB server. It provides load balancing and connection persistence functions for TiDB, making the workload of the TiDB cluster more balanced and not affecting user access to the database during maintenance operations.
-
+
In v8.0.0, TiProxy becomes generally available and enhances the automatic generation of signature certificates and monitoring functions.
The usage scenarios of TiProxy are as follows:
@@ -175,7 +175,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### SQL
-* Support a new DML type for handling a large amount of data (experimental) [#50215](https://github.com/pingcap/tidb/issues/50215) @[ekexium](https://github.com/ekexium) **tw@Oreoxmt**
+* Support a new DML type for handling a large amount of data (experimental) [#50215](https://github.com/pingcap/tidb/issues/50215) @[ekexium](https://github.com/ekexium)
Before v8.0.0, TiDB stores all transaction data in memory before committing. When processing a large amount of data, the memory required for transactions becomes a bottleneck that limits the transaction size that TiDB can handle. Although TiDB introduces non-transactional DML to attempt to solve the transaction size limitation by splitting SQL statements, this feature has various limitations and does not provide an ideal experience in actual scenarios.
@@ -185,35 +185,35 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
For more information, see [documentation](/system-variables.md#tidb_dml_type-new-in-v800).
-* Support using some expressions to set default column values when creating a table (experimental) [#50936](https://github.com/pingcap/tidb/issues/50936) @[zimulala](https://github.com/zimulala) **tw@hfxsd**
+* Support using some expressions to set default column values when creating a table (experimental) [#50936](https://github.com/pingcap/tidb/issues/50936) @[zimulala](https://github.com/zimulala)
Before v8.0.0, when you create a table, the default value of a column is limited to strings, numbers, and dates. Starting from v8.0.0, you can use some expressions as the default column values. For example, you can set the default value of a column to `UUID()`. This feature helps you meet more diverse requirements.
-
+
For more information, see [documentation](/data-type-default-values.md#specify-expressions-as-default-values).
-* Support the `div_precision_increment` system variable [#51501](https://github.com/pingcap/tidb/issues/51501) @[yibin87](https://github.com/yibin87) **tw@hfxsd**
+* Support the `div_precision_increment` system variable [#51501](https://github.com/pingcap/tidb/issues/51501) @[yibin87](https://github.com/yibin87)
MySQL 8.0 supports the variable `div_precision_increment`, which specifies the number of digits by which to increase the scale of the result of a division operation performed using the `/` operator. Before v8.0.0, TiDB does not support this variable, and division is performed to 4 decimal places. Starting from v8.0.0, TiDB supports this variable. You can specify the number of digits by which to increase the scale of the result of a division operation as desired.
-
+
For more information, see [documentation](/system-variables.md#div_precision_increment-new-in-v800).
-
+
### DB operations
-* PITR supports Amazon S3 Object Lock [#51184](https://github.com/pingcap/tidb/issues/51184) @[RidRisR](https://github.com/RidRisR) **tw@lilin90**
+* PITR supports Amazon S3 Object Lock [#51184](https://github.com/pingcap/tidb/issues/51184) @[RidRisR](https://github.com/RidRisR)
- Amazon S3 Object Lock can help prevent backup data from being accidentally or intentionally deleted during a specified retention period, enhancing the security and integrity of data. Starting from v6.3.0, BR supports Amazon S3 Object Lock in snapshot backups, adding an additional layer of security for full backups. Starting from v8.0.0, PITR also supports Amazon S3 Object Lock. Whether full backups or log data backups, the Object Lock feature ensures a more reliable data protection, further strengthening the security of data backup and recovery and meeting regulatory requirements.
+ Amazon S3 Object Lock can help prevent backup data from accidental or intentional deletion during a specified retention period, enhancing the security and integrity of data. Starting from v6.3.0, BR supports Amazon S3 Object Lock for snapshot backups, adding an additional layer of security for full backups. Starting from v8.0.0, PITR also supports Amazon S3 Object Lock. Whether for full backups or log data backups, the Object Lock feature ensures more reliable data protection, further strengthening the security of data backup and recovery and meeting regulatory requirements.
For more information, see [documentation](/br/backup-and-restore-storages.md#other-features-supported-by-the-storage-service).
-* Support making invisible indexes visible at the session level [#50653](https://github.com/pingcap/tidb/issues/50653) @[hawkingrei](https://github.com/hawkingrei) **tw@Oreoxmt**
+* Support making invisible indexes visible at the session level [#50653](https://github.com/pingcap/tidb/issues/50653) @[hawkingrei](https://github.com/hawkingrei)
- By default, the optimizer does not select [invisible indexes](/sql-statements/sql-statement-create-index.md#invisible-index) to optimize query execution. This mechanism is usually used to evaluate whether to delete an index. If there is uncertainty about the potential performance impact of deleting an index, you have the option to set the index to invisible temporarily and promptly restore it to visible when needed.
+ By default, the optimizer does not select [invisible indexes](/sql-statements/sql-statement-create-index.md#invisible-index). This mechanism is usually used to evaluate whether to delete an index. If there is uncertainty about the potential performance impact of deleting an index, you have the option to set the index to invisible temporarily and promptly restore it to visible when needed.
- Starting from v8.0.0, you can set the session-level system variable [`tidb_opt_use_invisible_indexes`](/system-variables.md#) to `ON` to make the current session recognize and use invisible indexes. With this feature, you can create a new index and test its performance by setting the index to invisible first, and then modifying the system variable in the current session for testing without affecting other sessions. This improvement enhances the safety of performance tuning and helps to improve the stability of production databases.
+ Starting from v8.0.0, you can set the session-level system variable [`tidb_opt_use_invisible_indexes`](/system-variables.md#tidb_opt_use_invisible_indexes-new-in-v800) to `ON` to make the current session recognize and use invisible indexes. With this feature, you can create a new index and test its performance by setting the index to invisible first, and then modifying the system variable in the current session for testing without affecting other sessions. This improvement enhances the safety of performance tuning and helps to improve the stability of production databases.
For more information, see [documentation](/sql-statements/sql-statement-create-index.md#invisible-index).
-* Support writing general logs to a separate file [#51248](https://github.com/pingcap/tidb/issues/51248) @[Defined2014](https://github.com/Defined2014) **tw@hfxsd**
+* Support writing general logs to a separate file [#51248](https://github.com/pingcap/tidb/issues/51248) @[Defined2014](https://github.com/Defined2014)
The general log is a MySQL-compatible feature that logs all executed SQL statements to help diagnose issues. TiDB also supports this feature. You can enable it by setting the variable [`tidb_general_log`](/system-variables.md#tidb_general_log). However, in previous versions, the content of general logs can only be written to the TiDB instance log along with other information, which is inconvenient for users who need to keep logs for a long time.
@@ -225,7 +225,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### Observability
-* Support monitoring index usage statistics [#49830](https://github.com/pingcap/tidb/issues/49830) @[YangKeao](https://github.com/YangKeao) **tw@Oreoxmt**
+* Support monitoring index usage statistics [#49830](https://github.com/pingcap/tidb/issues/49830) @[YangKeao](https://github.com/YangKeao)
Proper index design is a crucial prerequisite for improving database performance. TiDB v8.0.0 introduces the [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md) table, which records usage statistics of all indexes on the current TiDB node, including the following information:
@@ -235,22 +235,22 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
* The time of the most recent access to the index
With this information, you can identify indexes that are not used by the optimizer and indexes with poor filtering effects, thereby optimizing index design to improve database performance.
-
+
Additionally, TiDB v8.0.0 introduces a view [`sys.schema_unused_index`](/sys-schema.md), which is compatible with MySQL. This view records indexes that have not been used since the last start of TiDB. For clusters upgraded from versions earlier than v8.0.0, the `sys` schema and the views in it are not created automatically. You can manually create them by referring to [`sys`](/sys-schema.md).
For more information, see [documentation](/information-schema/information-schema-tidb-index-usage.md).
### Security
-* TiKV encryption at rest supports Google [Key Management Service (Cloud KMS)](https://cloud.google.com/docs/security/key-management-deep-dive?hl) (experimental) [#8906](https://github.com/tikv/tikv/issues/8906) @[glorv](https://github.com/glorv) **tw@qiancai**
+* TiKV encryption at rest supports Google [Key Management Service (Cloud KMS)](https://cloud.google.com/docs/security/key-management-deep-dive?hl) (experimental) [#8906](https://github.com/tikv/tikv/issues/8906) @[glorv](https://github.com/glorv)
TiKV ensures data security by encrypting stored data using the encryption at rest technique. The core of encryption at rest for security is key management. Starting from v8.0.0, you can manage the master key of TiKV using Google Cloud KMS to establish encryption-at-rest capabilities based on Cloud KMS, thereby enhancing the security of user data.
To enable encryption at rest based on Google Cloud KMS, you need to create a key on Google Cloud and then configure the `[security.encryption.master-key]` section in the TiKV configuration file.
- For more information, see [documentation](/encryption-at-rest.md##tikv-encryption-at-rest).
+ For more information, see [documentation](/encryption-at-rest.md#tikv-encryption-at-rest).
-* Enhance TiDB log desensitization [#51306](https://github.com/pingcap/tidb/issues/51306) @[xhebox](https://github.com/xhebox) **tw@hfxsd**
+* Enhance TiDB log desensitization [#51306](https://github.com/pingcap/tidb/issues/51306) @[xhebox](https://github.com/xhebox)
The enhancement of TiDB log desensitization is based on marking SQL text information in log files, facilitating the safe display of sensitive data when users view the logs. You can control whether to desensitize log information to enable secure use of TiDB logs in different scenarios, enhancing the security and flexibility of using log desensitization. To use this feature, set the system variable `tidb_redact_log` to `MARKER`. This marks the SQL text in TiDB logs. When you view the logs, sensitive data is securely displayed based on the markers, thus protecting the log information.
@@ -258,41 +258,41 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### Data migration
-* TiCDC adds support for the Simple protocol [#9898](https://github.com/pingcap/tiflow/issues/9898) @[3AceShowHand](https://github.com/3AceShowHand) **tw@lilin90**
+* TiCDC adds support for the Simple protocol [#9898](https://github.com/pingcap/tiflow/issues/9898) @[3AceShowHand](https://github.com/3AceShowHand)
TiCDC introduces a new protocol, the Simple protocol. This protocol provides in-band schema tracking capabilities by embedding table schema information in DDL and BOOTSTRAP events.
For more information, see [documentation](/ticdc/ticdc-simple-protocol.md).
-* TiCDC adds support for the Debezium format protocol [#1799](https://github.com/pingcap/tiflow/issues/1799) @[breezewish](https://github.com/breezewish) **tw@lilin90**
+* TiCDC adds support for the Debezium format protocol [#1799](https://github.com/pingcap/tiflow/issues/1799) @[breezewish](https://github.com/breezewish)
TiCDC can now publish data change events to a Kafka sink using a protocol that generates event messages in a Debezium style format. This helps to simplify the migration from MySQL to TiDB for users who are currently using Debezium to pull data from MySQL for downstream processing.
For more information, see [documentation](/ticdc/ticdc-debezium.md).
-* DM supports using a user-provided secret key to encrypt and decrypt passwords of source and target databases [#9492](https://github.com/pingcap/tiflow/issues/9492) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
+* DM supports using a user-provided secret key to encrypt and decrypt passwords of source and target databases [#9492](https://github.com/pingcap/tiflow/issues/9492) @[D3Hunter](https://github.com/D3Hunter)
In earlier versions, DM uses a built-in fixed secret key with relatively low security. Starting from v8.0.0, you can upload and specify a secret key file for encrypting and decrypting passwords of upstream and downstream databases. In addition, you can replace the secret key file as needed to enhance data security.
- For more information, see [documentation](dm/dm-customized-secret-key.md).
+ For more information, see [documentation](/dm/dm-customized-secret-key.md).
-* Supports the `IMPORT INTO ... FROM SELECT` syntax to enhance the `IMPORT INTO` functionality (experimental) [#49883](https://github.com/pingcap/tidb/issues/49883) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
+* Supports the `IMPORT INTO ... FROM SELECT` syntax to enhance the `IMPORT INTO` functionality (experimental) [#49883](https://github.com/pingcap/tidb/issues/49883) @[D3Hunter](https://github.com/D3Hunter)
In earlier TiDB versions, importing query results into a target table could only be done using the `INSERT INTO ... SELECT` statement, which is relatively inefficient in some large dataset scenarios. Starting from v8.0.0, TiDB enables you to use `IMPORT INTO ... FROM SELECT` to import the results of a `SELECT` query into an empty TiDB target table, which achieves up to 8 times the performance of `INSERT INTO ... SELECT` and significantly reduces the import time.
In addition, you can use `IMPORT INTO ... FROM SELECT` to import historical data queried with [`AS OF TIMESTAMP`](/as-of-timestamp.md).
- For more information, see [documentation](sql-statements/sql-statement-import-into.md).
+ For more information, see [documentation](/sql-statements/sql-statement-import-into.md).
-* TiDB Lightning simplifies conflict resolution strategies and supports handling conflicting data using the `replace` strategy (experimental) [#51036](https://github.com/pingcap/tidb/issues/51036) @[lyzx2001](https://github.com/lyzx2001) **tw@qiancai**
+* TiDB Lightning simplifies conflict resolution strategies and supports handling conflicting data using the `replace` strategy (experimental) [#51036](https://github.com/pingcap/tidb/issues/51036) @[lyzx2001](https://github.com/lyzx2001)
- In earlier versions, TiDB Lightning has [one data conflict resolution strategy](/tidb-lightning/tidb-lightning-logical-import-mode-usage.md#conflict-detection) for the logical import mode and [two data conflict resolution strategies](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#conflict-data-detection) for the physical import mode, which are not easy to understand and configure.
+ In earlier versions, TiDB Lightning has [one data conflict resolution strategy](/tidb-lightning/tidb-lightning-logical-import-mode-usage.md#conflict-detection) for the logical import mode and [two data conflict resolution strategies](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#conflict-detection) for the physical import mode, which are not easy to understand and configure.
- Starting from v8.0.0, TiDB Lightning deprecates the [old version of conflict detection](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#the-old-version-of-conflict-detection-deprecated-in-v800) strategy for the physical import mode, enables you to control the conflict detection strategy for both logical and physical import modes via the [`conflict.strategy`](tidb-lightning/tidb-lightning-configuration.md) parameter, and simplifies the configuration of this parameter. In addition, in the physical import mode, the `replace` strategy now supports retaining the latest data and overwriting the old data when the import detects data with primary key or unique key conflicts.
+ Starting from v8.0.0, TiDB Lightning deprecates the [old version of conflict detection](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#the-old-version-of-conflict-detection-deprecated-in-v800) strategy for the physical import mode, enables you to control the conflict detection strategy for both logical and physical import modes via the [`conflict.strategy`](/tidb-lightning/tidb-lightning-configuration.md) parameter, and simplifies the configuration of this parameter. In addition, in the physical import mode, the `replace` strategy now supports retaining the latest data and overwriting the old data when the import detects data with primary key or unique key conflicts.
- For more information, see [documentation](tidb-lightning/tidb-lightning-configuration.md).
+ For more information, see [documentation](/tidb-lightning/tidb-lightning-configuration.md).
-* Global Sort becomes generally available (GA), improving the performance and stability of `IMPORT INTO` significantly [#45719](https://github.com/pingcap/tidb/issues/45719) @[lance6716](https://github.com/lance6716) **tw@qiancai**
+* Global Sort becomes generally available (GA), improving the performance and stability of `IMPORT INTO` significantly [#45719](https://github.com/pingcap/tidb/issues/45719) @[lance6716](https://github.com/lance6716)
Before v7.4.0, when executing `IMPORT INTO` tasks using the [Distributed eXecution Framework (DXF)](/tidb-distributed-execution-framework.md), TiDB only locally sorts part of the data before importing it into TiKV due to limited local storage space. This results in significant overlap of the imported data in TiKV, requiring TiKV to perform additional compaction operations during import and affecting the TiKV performance and stability.
@@ -312,11 +312,11 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
### Behavior changes
-* Before v8.0.0, after enabling the acceleration of `ADD INDEX` and `CREATE INDEX` (`tidb_ddl_enable_fast_reorg = ON`), the encoded index key ingests data to TiKV with a fixed concurrency of `16`, which cannot be dynamically adjusted according to the downstream TiKV capacity. Starting from v8.0.0, you can adjust the concurrency using the [`tidb_ddl_reorg_worker_cnt`](/system-variables.md#tidb_ddl_reorg_worker_cnt-new-in-v800) system variable. The default value is `4`. Compared with the previous default value of `16`, the new default value reduces performance when ingesting indexed key-value pairs. You can adjust this system variable based on the workload of your cluster. **tw@hfxsd**
+* Before v8.0.0, after enabling the acceleration of `ADD INDEX` and `CREATE INDEX` (`tidb_ddl_enable_fast_reorg = ON`), the encoded index key ingests data to TiKV with a fixed concurrency of `16`, which cannot be dynamically adjusted according to the downstream TiKV capacity. Starting from v8.0.0, you can adjust the concurrency using the [`tidb_ddl_reorg_worker_cnt`](/system-variables.md#tidb_ddl_reorg_worker_cnt) system variable. The default value is `4`. Compared with the previous default value of `16`, the new default value reduces performance when ingesting indexed key-value pairs. You can adjust this system variable based on the workload of your cluster.
-### MySQL compatibility
+### MySQL compatibility
-* The `KEY` partition type supports statements with an empty list of partition fields, which is consistent with the behavior of MySQL. **tw@hfxsd**
+* The `KEY` partition type supports statements with an empty list of partition fields, which is consistent with the behavior of MySQL.
### System variables
@@ -345,7 +345,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
| TiDB | [`log.file.compression`](/tidb-configuration-file.md#compression-new-in-v800) | Newly added | Specifies the compression format of the polling log. The default value is null, which means that the polling log is not compressed. |
| TiDB | [`log.general-log-file`](/tidb-configuration-file.md#general-log-file-new-in-v800) | Newly added | Specifies the file to save the general log to. The default is null, which means that the general log will be written to the instance file. |
| TiDB | [`tikv-client.enable-replica-selector-v2`](/tidb-configuration-file.md#enable-replica-selector-v2-new-in-v800) | Newly added | Controls whether to use the new version of the Region replica selector when sending RPC requests to TiKV. The default value is `true`. |
-| TiKV | [`log-backup.initial-scan-rate-limit`](/system-variables.md#initial-scan-rate-limit-new-in-v620) | Modified | Adds a limit of `1MiB` as the minimum value. |
+| TiKV | [`log-backup.initial-scan-rate-limit`](/tikv-configuration-file.md#initial-scan-rate-limit-new-in-v620) | Modified | Adds a limit of `1MiB` as the minimum value. |
| TiKV | [`raftstore.store-io-pool-size`](/tikv-configuration-file.md#store-io-pool-size-new-in-v530) | Modified | Changes the default value from `0` to `1` to improve TiKV performance, meaning that the size of the StoreWriter thread pool now defaults to `1`. |
| TiKV | [`rocksdb.defaultcf.titan.blob-cache-size`](/tikv-configuration-file.md#blob-cache-size) | Modified | Starting from v8.0.0, TiKV introduces the `shared-blob-cache` configuration item and enables it by default, so there is no need to set `blob-cache-size` separately. The configuration of `blob-cache-size` only takes effect when `shared-blob-cache` is set to `false`. |
| TiKV | [`security.encryption.master-key.vendor`](/encryption-at-rest.md#specify-a-master-key-via-kms) | Modified | Adds `gcp` as an available type for the service provider. |
@@ -356,29 +356,29 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
| TiDB Lightning | [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) | Newly added | Controls the maximum number of rows inserted per transaction in Logical Import Mode. The default value is `65536` rows. |
| TiDB Lightning | [`logical-import-batch-size`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) | Newly added | Controls the size of each SQL query executed on the downstream TiDB server in Logical Import Mode. The default value is `"96KiB"`. The unit can be KB, KiB, MB, or MiB. |
| Data Migration | [`secret-key-path`](/dm/dm-master-configuration-file.md) | Newly added | Specifies the file path of the secret key, which is used to encrypt and decrypt upstream and downstream passwords. The file must contain a 64-character hexadecimal AES-256 secret key. |
-| TiCDC | [`tls-certificate-file`](ticdc/ticdc-sink-to-pulsar.md) | Newly added | Specifies the path to the encrypted certificate file on the client, which is required when Pulsar enables TLS encrypted transmission. |
-| TiCDC | [`tls-key-file-path`](ticdc/ticdc-sink-to-pulsar.md) | Newly added | Specifies the path to the encrypted private key on the client, which is required when Pulsar enables TLS encrypted transmission. |
+| TiCDC | [`tls-certificate-file`](/ticdc/ticdc-sink-to-pulsar.md) | Newly added | Specifies the path to the encrypted certificate file on the client, which is required when Pulsar enables TLS encrypted transmission. |
+| TiCDC | [`tls-key-file-path`](/ticdc/ticdc-sink-to-pulsar.md) | Newly added | Specifies the path to the encrypted private key on the client, which is required when Pulsar enables TLS encrypted transmission. |
### System tables
-* Add new system tables [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md) and [`INFORMATION_SCHEMA.CLUSTER_TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md#cluster_tidb_index_usage) to record index usage statistics on TiDB nodes. **tw@Oreoxmt**
-* Add a new system schema [`sys`](/sys-schema.md) and a new view [`sys.schema_unused_index`](/sys-schema.md#schema_unused_index), which records indexes that have not been used since the last start of TiDB. **tw@Oreoxmt**
+* Add new system tables [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md) and [`INFORMATION_SCHEMA.CLUSTER_TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md#cluster_tidb_index_usage) to record index usage statistics on TiDB nodes.
+* Add a new system schema [`sys`](/sys-schema.md) and a new view [`sys.schema_unused_index`](/sys-schema.md#schema_unused_index), which records indexes that have not been used since the last start of TiDB.
## Deprecated features
-- Starting from v8.0.0, the [`tidb_disable_txn_auto_retry`](/system-variables.md#tidb_disable_txn_auto_retry) system variable is deprecated, and TiDB no longer supports automatic retries of optimistic transactions. As an alternative, when encountering optimistic transaction conflicts, you can capture the error and retry transactions in your application, or use the [Pessimistic transaction mode](/pessimistic-transaction.md) instead. **tw@lilin90**
+- Starting from v8.0.0, the [`tidb_disable_txn_auto_retry`](/system-variables.md#tidb_disable_txn_auto_retry) system variable is deprecated, and TiDB no longer supports automatic retries of optimistic transactions. As an alternative, when encountering optimistic transaction conflicts, you can capture the error and retry transactions in your application, or use the [Pessimistic transaction mode](/pessimistic-transaction.md) instead.
- Starting from v8.0.0, TiDB no longer supports the TLSv1.0 and TLSv1.1 protocols. You must upgrade TLS to TLSv1.2 or TLSv1.3.
- It is planned to redesign [the auto-evolution of execution plan bindings](/sql-plan-management.md#baseline-evolution) in subsequent releases, and the related variables and behavior will change.
## Improvements
-+ TiDB
++ TiDB
- Improve the performance of executing the `CREATE TABLE` DDL statement by 10 times and support linear scalability [#50052](https://github.com/pingcap/tidb/issues/50052) @[GMHDBJD](https://github.com/GMHDBJD)
- - Support submitting 16 `IMPORT INTO ... FROM FILE` tasks simultaneously, facilitating bulk data import into target tables and significantly improving the efficiency and performance of importing data files [#49008](https://github.com/pingcap/tidb/issues/49008) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
- - Improve the performance of spilling data to disk for the `Sort` operator [#47733](https://github.com/pingcap/tidb/issues/47733) @[xzhangxian1008](https://github.com/xzhangxian1008) **tw@Oreoxmt**
- - Support canceling queries during spilling data to disk, which optimizes the exit mechanism of the data spill feature [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12) **tw@qiancai**
- - Support using an index that matches partial conditions to construct Index Join when processing table join queries with multiple equal conditions [#47233](https://github.com/pingcap/tidb/issues/47233) @[winoros](https://github.com/winoros) **tw@Oreoxmt**
+ - Support submitting 16 `IMPORT INTO ... FROM FILE` tasks simultaneously, facilitating bulk data import into target tables and significantly improving the efficiency and performance of importing data files [#49008](https://github.com/pingcap/tidb/issues/49008) @[D3Hunter](https://github.com/D3Hunter)
+ - Improve the performance of spilling data to disk for the `Sort` operator [#47733](https://github.com/pingcap/tidb/issues/47733) @[xzhangxian1008](https://github.com/xzhangxian1008)
+ - Support canceling queries during spilling data to disk, which optimizes the exit mechanism of the data spill feature [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12)
+ - Support using an index that matches partial conditions to construct Index Join when processing table join queries with multiple equal conditions [#47233](https://github.com/pingcap/tidb/issues/47233) @[winoros](https://github.com/winoros)
- Enhance the capability of Index Merge to identify sorting requirements in queries and select indexes that meet the sorting requirements [#48359](https://github.com/pingcap/tidb/issues/48359) @[AilinKid](https://github.com/AilinKid)
- When the `Apply` operator is not executed concurrently, TiDB enables you to view the name of the operator that blocks the concurrency by executing `SHOW WARNINGS` [#50256](https://github.com/pingcap/tidb/issues/50256) @[hawkingrei](https://github.com/hawkingrei)
- Optimize the index selection for `point get` queries by selecting the most optimal index for queries when all indexes support `point get` queries [#50184](https://github.com/pingcap/tidb/issues/50184) @[elsa0520](https://github.com/elsa0520)
@@ -386,13 +386,17 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
- When the `PREPARE` statement fails to hit the execution plan cache, TiDB enables you to view the reason by executing `SHOW WARNINGS` [#50407](https://github.com/pingcap/tidb/issues/50407) @[hawkingrei](https://github.com/hawkingrei)
- Improve the accuracy of query estimation information when the same row of data is updated multiple times [#47523](https://github.com/pingcap/tidb/issues/47523) @[terry1purcell](https://github.com/terry1purcell)
- Index Merge supports embedding multi-value indexes and `OR` operators in `AND` predicates [#51778](https://github.com/pingcap/tidb/issues/51778) @[time-and-fate](https://github.com/time-and-fate)
- - (dup): release-7.1.4.md > Improvements> TiDB - When `force-init-stats` is set to `true`, TiDB waits for statistics initialization to finish before providing services during TiDB startup. This setting no longer blocks the startup of HTTP servers, which enables users to continue monitoring [#50854](https://github.com/pingcap/tidb/issues/50854) @[hawkingrei](https://github.com/hawkingrei)
+ - When `force-init-stats` is set to `true`, TiDB waits for statistics initialization to finish before providing services during TiDB startup. This setting no longer blocks the startup of HTTP servers, which enables users to continue monitoring [#50854](https://github.com/pingcap/tidb/issues/50854) @[hawkingrei](https://github.com/hawkingrei)
+ - MemoryTracker can track the memory usage of the `IndexLookup` operator [#45901](https://github.com/pingcap/tidb/issues/45901) @[solotzg](https://github.com/solotzg)
+ - MemoryTracker can track the memory usage of the `MemTableReaderExec` operator [#51456](https://github.com/pingcap/tidb/issues/51456) @[wshwsh12](https://github.com/wshwsh12)
+ - Support running cancel-aware on the queries that are being spilled [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12)
+ - Support loading Regions in batch from PD to speed up the conversion process from the KV range to Regions when querying large tables [#51326](https://github.com/pingcap/tidb/issues/51326) @[SeaRise](https://github.com/SeaRise)
-+ TiKV
++ TiKV
- Enhance TSO verification and detection to improve the robustness of the cluster TSO when the configuration or operation is improper [#16545](https://github.com/tikv/tikv/issues/16545) @[cfzjywxk](https://github.com/cfzjywxk)
- Optimize the logic of cleaning up pessimistic locks to improve the processing performance of uncommitted transactions [#16158](https://github.com/tikv/tikv/issues/16158) @[cfzjywxk](https://github.com/cfzjywxk)
- - Introduce unified health control for TiKV to reduce the impact of abnormal single TiKV node on cluster access performance. You can disable this optimization by setting [`tikv-client.enable-replica-selector-v2`](/tidb-configuration-file.md#enable-replica-selector-v2-new-in-v800) to `false`. [#16297](https://github.com/tikv/tikv/issues/16297) [#1104](https://github.com/tikv/client-go/issues/1104) [#1167](https://github.com/tikv/client-go/issues/1167) @[MyonKeminta](https://github.com/MyonKeminta) @[zyguan](https://github.com/zyguan) @[crazycs520](https://github.com/crazycs520) **tw@qiancai**
+ - Introduce unified health control for TiKV to reduce the impact of abnormal single TiKV node on cluster access performance. You can disable this optimization by setting [`tikv-client.enable-replica-selector-v2`](/tidb-configuration-file.md#enable-replica-selector-v2-new-in-v800) to `false`. [#16297](https://github.com/tikv/tikv/issues/16297) [#1104](https://github.com/tikv/client-go/issues/1104) [#1167](https://github.com/tikv/client-go/issues/1167) @[MyonKeminta](https://github.com/MyonKeminta) @[zyguan](https://github.com/zyguan) @[crazycs520](https://github.com/crazycs520)
- The PD client uses the metadata storage interface to replace the previous global configuration interface [#14484](https://github.com/tikv/tikv/issues/14484) @[HuSharp](https://github.com/HuSharp)
- Enhance the scanning performance by determining the data loading behavior through write cf stats [#16245](https://github.com/tikv/tikv/issues/16245) @[Connor1996](https://github.com/Connor1996)
- Check the latest heartbeat for nodes being deleted and voters being demoted during the Raft conf change process to ensure that this behavior does not make the Region inaccessible [#15799](https://github.com/tikv/tikv/issues/15799) @[tonyxuqqi](https://github.com/tonyxuqqi)
@@ -401,7 +405,7 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
- Add CPU monitoring for Region workers and snapshot generation workers [#16562](https://github.com/tikv/tikv/issues/16562) @[Connor1996](https://github.com/Connor1996)
- Add slow logs for peer and store messages [#16600](https://github.com/tikv/tikv/issues/16600) @[Connor1996](https://github.com/Connor1996)
-+ PD
++ PD
- Enhance the service discovery capability of the PD client to improve its high availability and load balancing [#7576](https://github.com/tikv/pd/issues/7576) @[CabinfeverB](https://github.com/CabinfeverB)
- Enhance the retry mechanism of the PD client [#7673](https://github.com/tikv/pd/issues/7673) @[JmPotato](https://github.com/JmPotato)
@@ -415,29 +419,35 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
- Reduce the lock contention issue in creating operators [#7837](https://github.com/tikv/pd/issues/7837) @[Leavrth](https://github.com/Leavrth)
- Adjust GRPC configurations to improve availability [#7821](https://github.com/tikv/pd/issues/7821) @[rleungx](https://github.com/rleungx)
++ TiFlash
+
+ - Support using non-constant values for the `json_path` argument in the `JSON_EXTRACT()` function [#8510](https://github.com/pingcap/tiflash/issues/8510) @[SeaRise](https://github.com/SeaRise)
+ - Support two arguments for the `JSON_LENGTH(json, path)` function [#8711](https://github.com/pingcap/tiflash/issues/8711) @[SeaRise](https://github.com/SeaRise)
+
+ Tools
- + Backup & Restore (BR)
+ + Backup & Restore (BR)
- - Support controlling whether to restore statistics using the newly added restore parameter `--load-stats` [#50568](https://github.com/pingcap/tidb/issues/50568) @[Leavrth](https://github.com/Leavrth)
+ - Introduce a new restore parameter `--load-stats` for the `br` command-line tool, which controls whether to restore statistics [#50568](https://github.com/pingcap/tidb/issues/50568) @[Leavrth](https://github.com/Leavrth)
+ - Introduce a new restore parameter `--tikv-max-restore-concurrency` for the `br` command-line tool, which controls the maximum number of download and ingest files for each TiKV node. This parameter also controls the memory consumption of a BR node by controlling the maximum length of the job queue. [#51621](https://github.com/pingcap/tidb/issues/51621) @[3pointer](https://github.com/3pointer)
- Enhance restore performance by enabling the coarse-grained Region scatter algorithm to adaptively obtain concurrent parameters [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer)
- Display the `log` command in the command-line help information of `br` [#50927](https://github.com/pingcap/tidb/issues/50927) @[RidRisR](https://github.com/RidRisR)
- Support pre-allocating Table ID during the restore process to maximize the reuse of Table ID and improve restore performance [#51736](https://github.com/pingcap/tidb/issues/51736) @[Leavrth](https://github.com/Leavrth)
- Disable the GC memory limit tuner feature within TiDB when using BR to avoid OOM issues [#51078](https://github.com/pingcap/tidb/issues/51078) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Improvements> Tools> Backup & Restore (BR) - Improve the speed of merging SST files during data restore by using a more efficient algorithm [#50613](https://github.com/pingcap/tidb/issues/50613) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Improvements> Tools> Backup & Restore (BR) - Support creating databases in batch during data restore [#50767](https://github.com/pingcap/tidb/issues/50767) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Improvements> Tools> Backup & Restore (BR) - Print the information of the slowest Region that affects global checkpoint advancement in logs and metrics during log backups [#51046](https://github.com/pingcap/tidb/issues/51046) @[YuJuncen](https://github.com/YuJuncen)
- - (dup): release-7.5.1.md > Improvements> Tools> Backup & Restore (BR) - Improve the table creation performance of the `RESTORE` statement in scenarios with large datasets [#48301](https://github.com/pingcap/tidb/issues/48301) @[Leavrth](https://github.com/Leavrth)
+ - Improve the speed of merging SST files during data restore by using a more efficient algorithm [#50613](https://github.com/pingcap/tidb/issues/50613) @[Leavrth](https://github.com/Leavrth)
+ - Support creating databases in batch during data restore [#50767](https://github.com/pingcap/tidb/issues/50767) @[Leavrth](https://github.com/Leavrth)
+ - Print the information of the slowest Region that affects global checkpoint advancement in logs and metrics during log backups [#51046](https://github.com/pingcap/tidb/issues/51046) @[YuJuncen](https://github.com/YuJuncen)
+ - Improve the table creation performance of the `RESTORE` statement in scenarios with large datasets [#48301](https://github.com/pingcap/tidb/issues/48301) @[Leavrth](https://github.com/Leavrth)
- + TiCDC
+ + TiCDC
- Optimize the memory consumption of `RowChangedEvent` to reduce memory consumption when TiCDC replicates data [#10386](https://github.com/pingcap/tiflow/issues/10386) @[lidezhu](https://github.com/lidezhu)
- Verify that the start-ts parameter is valid when creating and resuming a changefeed task [#10499](https://github.com/pingcap/tiflow/issues/10499) @[3AceShowHand](https://github.com/3AceShowHand)
+ TiDB Data Migration (DM)
- - In a MariaDB primary-secondary replication scenario, where the migration path is: MariaDB primary instance -> MariaDB secondary instance -> DM -> TiDB, when `gtid_strict_mode = off` and the GTID of the MariaDB secondary instance is not strictly incrementing (for example, there is data writing to the MariaDB secondary instance), the DM task will report an error `less than global checkpoint position`. Starting from v8.0.0, TiDB is compatible with this scenario and data can be migrated downstream normally. [#10741](https://github.com/pingcap/tiflow/issues/10741) @[okJiang](https://github.com/okJiang) **tw@hfxsd**
-
+ - In a MariaDB primary-secondary replication scenario, where the migration path is: MariaDB primary instance -> MariaDB secondary instance -> DM -> TiDB, when `gtid_strict_mode = off` and the GTID of the MariaDB secondary instance is not strictly incrementing (for example, there is data writing to the MariaDB secondary instance), the DM task will report an error `less than global checkpoint position`. Starting from v8.0.0, TiDB is compatible with this scenario and data can be migrated downstream normally. [#10741](https://github.com/pingcap/tiflow/issues/10741) @[okJiang](https://github.com/okJiang)
+
+ TiDB Lightning
-
+
- Support configuring the maximum number of rows in a batch in logical import mode using [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) [#46607](https://github.com/pingcap/tidb/issues/46607) @[kennytm](https://github.com/kennytm)
- TiDB Lightning reports an error when the space of TiFlash is insufficient [#50324](https://github.com/pingcap/tidb/issues/50324) @[okJiang](https://github.com/okJiang)
@@ -448,15 +458,15 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
- Fix the issue that `auto analyze` is triggered multiple times when there is no data change [#51775](https://github.com/pingcap/tidb/issues/51775) @[hi-rustin](https://github.com/hi-rustin)
- Fix the issue that the `auto analyze` concurrency is set incorrectly [#51749](https://github.com/pingcap/tidb/issues/51749) @[hawkingrei](https://github.com/hawkingrei)
- Fix the issue of index inconsistency caused by adding multiple indexes using a single SQL statement [#51746](https://github.com/pingcap/tidb/issues/51746) @[tangenta](https://github.com/tangenta)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the `Column ... in from clause is ambiguous` error that might occur when a query uses `NATURAL JOIN` [#32044](https://github.com/pingcap/tidb/issues/32044) @[AilinKid](https://github.com/AilinKid)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue of wrong query results due to TiDB incorrectly eliminating constant values in `group by` [#38756](https://github.com/pingcap/tidb/issues/38756) @[hi-rustin](https://github.com/hi-rustin)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that the `LEADING` hint does not take effect in `UNION ALL` statements [#50067](https://github.com/pingcap/tidb/issues/50067) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that `BIT` type columns might cause query errors due to decode failures when they are involved in calculations of some functions [#49566](https://github.com/pingcap/tidb/issues/49566) [#50850](https://github.com/pingcap/tidb/issues/50850) [#50855](https://github.com/pingcap/tidb/issues/50855) @[jiyfhust](https://github.com/jiyfhust)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that TiDB might panic when performing a rolling upgrade using `tiup cluster upgrade/start` due to an interaction issue with PD [#50152](https://github.com/pingcap/tidb/issues/50152) @[zimulala](https://github.com/zimulala)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that executing `UNIQUE` index lookup with an `ORDER BY` clause might cause an error [#49920](https://github.com/pingcap/tidb/issues/49920) @[jackysp](https://github.com/jackysp)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that TiDB returns wrong query results when processing `ENUM` or `SET` types by constant propagation [#49440](https://github.com/pingcap/tidb/issues/49440) @[winoros](https://github.com/winoros)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that TiDB might panic when a query contains the Apply operator and the `fatal error: concurrent map writes` error occurs [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that the control of `SET_VAR` for variables of the string type might become invalid [#50507](https://github.com/pingcap/tidb/issues/50507) @[qw4990](https://github.com/qw4990)
+ - Fix the `Column ... in from clause is ambiguous` error that might occur when a query uses `NATURAL JOIN` [#32044](https://github.com/pingcap/tidb/issues/32044) @[AilinKid](https://github.com/AilinKid)
+ - Fix the issue of wrong query results due to TiDB incorrectly eliminating constant values in `group by` [#38756](https://github.com/pingcap/tidb/issues/38756) @[hi-rustin](https://github.com/hi-rustin)
+ - Fix the issue that the `LEADING` hint does not take effect in `UNION ALL` statements [#50067](https://github.com/pingcap/tidb/issues/50067) @[hawkingrei](https://github.com/hawkingrei)
+ - Fix the issue that `BIT` type columns might cause query errors due to decode failures when they are involved in calculations of some functions [#49566](https://github.com/pingcap/tidb/issues/49566) [#50850](https://github.com/pingcap/tidb/issues/50850) [#50855](https://github.com/pingcap/tidb/issues/50855) @[jiyfhust](https://github.com/jiyfhust)
+ - Fix the issue that TiDB might panic when performing a rolling upgrade using `tiup cluster upgrade/start` due to an interaction issue with PD [#50152](https://github.com/pingcap/tidb/issues/50152) @[zimulala](https://github.com/zimulala)
+ - Fix the issue that executing `UNIQUE` index lookup with an `ORDER BY` clause might cause an error [#49920](https://github.com/pingcap/tidb/issues/49920) @[jackysp](https://github.com/jackysp)
+ - Fix the issue that TiDB returns wrong query results when processing `ENUM` or `SET` types by constant propagation [#49440](https://github.com/pingcap/tidb/issues/49440) @[winoros](https://github.com/winoros)
+ - Fix the issue that TiDB might panic when a query contains the Apply operator and the `fatal error: concurrent map writes` error occurs [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
+ - Fix the issue that the control of `SET_VAR` for variables of the string type might become invalid [#50507](https://github.com/pingcap/tidb/issues/50507) @[qw4990](https://github.com/qw4990)
- Fix the issue that the `SYSDATE()` function incorrectly uses the time in the plan cache when `tidb_sysdate_is_now` is set to `1` [#49299](https://github.com/pingcap/tidb/issues/49299) @[hawkingrei](https://github.com/hawkingrei)
- Fix the issue that when executing the `CREATE GLOBAL BINDING` statement, if the schema name is in uppercase, the binding does not take effect [#50646](https://github.com/pingcap/tidb/issues/50646) @[qw4990](https://github.com/qw4990)
- Fix the issue that `Index Path` selects duplicated indexes [#50496](https://github.com/pingcap/tidb/issues/50496) @[AilinKid](https://github.com/AilinKid)
@@ -473,72 +483,82 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
- Fix the issue that the `init-stats` process might cause TiDB to panic and the `load stats` process to quit [#51581](https://github.com/pingcap/tidb/issues/51581) @[hawkingrei](https://github.com/hawkingrei)
- Fix the issue that the query result is incorrect when the `IN()` predicate contains `NULL` [#51560](https://github.com/pingcap/tidb/issues/51560) @[winoros](https://github.com/winoros)
- Fix the issue that blocked DDL statements are not displayed in the MDL View when a DDL task involves multiple tables [#47743](https://github.com/pingcap/tidb/issues/47743) @[wjhuang2016](https://github.com/wjhuang2016)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the issue that the `processed_rows` of the `ANALYZE` task on a table might exceed the total number of rows in that table [#50632](https://github.com/pingcap/tidb/issues/50632) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the goroutine leak issue that might occur when the `HashJoin` operator fails to spill to disk [#50841](https://github.com/pingcap/tidb/issues/50841) @[wshwsh12](https://github.com/wshwsh12)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the goroutine leak issue that occurs when the memory usage of CTE queries exceed limits [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
- - (dup): release-7.5.1.md > Bug fixes> TiDB - Fix the `Can't find column ...` error that might occur when aggregate functions are used for group calculations [#50926](https://github.com/pingcap/tidb/issues/50926) @[qw4990](https://github.com/qw4990)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that DDL operations such as renaming tables are stuck when the `CREATE TABLE` statement contains specific partitions or constraints [#50972](https://github.com/pingcap/tidb/issues/50972) @[lcwangchao](https://github.com/lcwangchao)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that the monitoring metric `tidb_statistics_auto_analyze_total` on Grafana is not displayed as an integer [#51051](https://github.com/pingcap/tidb/issues/51051) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that the `tidb_gogc_tuner_threshold` system variable is not adjusted accordingly after the `tidb_server_memory_limit` variable is modified [#48180](https://github.com/pingcap/tidb/issues/48180) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that the `index out of range` error might occur when a query involves JOIN operations [#42588](https://github.com/pingcap/tidb/issues/42588) @[AilinKid](https://github.com/AilinKid)
- - (dup): release-7.1.4.md > Bug fixes> TiDB - Fix the issue that getting the default value of a column returns an error if the column default value is dropped [#50043](https://github.com/pingcap/tidb/issues/50043) [#51324](https://github.com/pingcap/tidb/issues/51324) @[crazycs520](https://github.com/crazycs520)
+ - Fix the issue that the `processed_rows` of the `ANALYZE` task on a table might exceed the total number of rows in that table [#50632](https://github.com/pingcap/tidb/issues/50632) @[hawkingrei](https://github.com/hawkingrei)
+ - Fix the goroutine leak issue that might occur when the `HashJoin` operator fails to spill to disk [#50841](https://github.com/pingcap/tidb/issues/50841) @[wshwsh12](https://github.com/wshwsh12)
+ - Fix the goroutine leak issue that occurs when the memory usage of CTE queries exceed limits [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
+ - Fix the `Can't find column ...` error that might occur when aggregate functions are used for group calculations [#50926](https://github.com/pingcap/tidb/issues/50926) @[qw4990](https://github.com/qw4990)
+ - Fix the issue that DDL operations such as renaming tables are stuck when the `CREATE TABLE` statement contains specific partitions or constraints [#50972](https://github.com/pingcap/tidb/issues/50972) @[lcwangchao](https://github.com/lcwangchao)
+ - Fix the issue that the monitoring metric `tidb_statistics_auto_analyze_total` on Grafana is not displayed as an integer [#51051](https://github.com/pingcap/tidb/issues/51051) @[hawkingrei](https://github.com/hawkingrei)
+ - Fix the issue that the `tidb_gogc_tuner_threshold` system variable is not adjusted accordingly after the `tidb_server_memory_limit` variable is modified [#48180](https://github.com/pingcap/tidb/issues/48180) @[hawkingrei](https://github.com/hawkingrei)
+ - Fix the issue that the `index out of range` error might occur when a query involves JOIN operations [#42588](https://github.com/pingcap/tidb/issues/42588) @[AilinKid](https://github.com/AilinKid)
+ - Fix the issue that getting the default value of a column returns an error if the column default value is dropped [#50043](https://github.com/pingcap/tidb/issues/50043) [#51324](https://github.com/pingcap/tidb/issues/51324) @[crazycs520](https://github.com/crazycs520)
- Fix the issue that wrong results might be returned when TiFlash late materialization processes associated columns [#49241](https://github.com/pingcap/tidb/issues/49241) [#51204](https://github.com/pingcap/tidb/issues/51204) @[Lloyd-Pottiger](https://github.com/Lloyd-Pottiger)
+ - Fix the issue that the `LIKE()` function might return wrong results when processing binary collation inputs [#50393](https://github.com/pingcap/tidb/issues/50393) @[yibin87](https://github.com/yibin87)
+ - Fix the issue that TiDB might crash due to concurrent writes during parallel `Apply` [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
+ - Fix the issue that the `JSON_LENGTH()` function returns wrong results when the second parameter is `NULL` [#50931](https://github.com/pingcap/tidb/issues/50931) @[SeaRise](https://github.com/SeaRise)
+ - Fix the issue that queries containing `CTE` might cause Goroutine leaks when memory exceeds the limit [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
+ - Fix the issue that `CAST(AS DATETIME)` might lose time precision under certain circumstances [#49555](https://github.com/pingcap/tidb/issues/49555) @[SeaRise](https://github.com/SeaRise)
+ - Fix the issue that parallel `Apply` might generate incorrect results when the table has a clustered index [#51372](https://github.com/pingcap/tidb/issues/51372) @[guo-shaoge](https://github.com/guo-shaoge)
+ - Fix the issue that `ALTER TABLE ... COMPACT TIFLASH REPLICA` might incorrectly end when the primary key type is `VARCHAR` [#51810](https://github.com/pingcap/tidb/issues/51810) @[breezewish](https://github.com/breezewish)
+ TiKV
- - (dup): release-7.5.1.md > Bug fixes> TiKV - Fix the issue that enabling `tidb_enable_row_level_checksum` might cause TiKV to panic [#16371](https://github.com/tikv/tikv/issues/16371) @[cfzjywxk](https://github.com/cfzjywxk)
- - (dup): release-7.1.4.md > Bug fixes> TiKV - Fix the issue that hibernated Regions are not promptly awakened in exceptional circumstances [#16368](https://github.com/tikv/tikv/issues/16368) @[LykxSassinator](https://github.com/LykxSassinator)
- - (dup): release-7.1.4.md > Bug fixes> TiKV - Fix the issue that the entire Region becomes unavailable when one replica is offline, by checking the last heartbeat time of all replicas of the Region before taking a node offline [#16465](https://github.com/tikv/tikv/issues/16465) @[tonyxuqqi](https://github.com/tonyxuqqi)
- - (dup): release-7.1.4.md > Bug fixes> TiKV - Fix the issue that JSON integers greater than the maximum `INT64` value but less than the maximum `UINT64` value are parsed as `FLOAT64` by TiKV, resulting in inconsistency with TiDB [#16512](https://github.com/tikv/tikv/issues/16512) @[YangKeao](https://github.com/YangKeao)
+ - Fix the issue that enabling `tidb_enable_row_level_checksum` might cause TiKV to panic [#16371](https://github.com/tikv/tikv/issues/16371) @[cfzjywxk](https://github.com/cfzjywxk)
+ - Fix the issue that hibernated Regions are not promptly awakened in exceptional circumstances [#16368](https://github.com/tikv/tikv/issues/16368) @[LykxSassinator](https://github.com/LykxSassinator)
+ - Fix the issue that the entire Region becomes unavailable when one replica is offline, by checking the last heartbeat time of all replicas of the Region before taking a node offline [#16465](https://github.com/tikv/tikv/issues/16465) @[tonyxuqqi](https://github.com/tonyxuqqi)
+ - Fix the issue that JSON integers greater than the maximum `INT64` value but less than the maximum `UINT64` value are parsed as `FLOAT64` by TiKV, resulting in inconsistency with TiDB [#16512](https://github.com/tikv/tikv/issues/16512) @[YangKeao](https://github.com/YangKeao)
- Fix the issue that the monitoring metric `tikv_unified_read_pool_thread_count` has no data in some cases [#16629](https://github.com/tikv/tikv/issues/16629) @[YuJuncen](https://github.com/YuJuncen)
-
-+ PD
-
- - (dup): release-7.1.4.md > Bug fixes> PD - Fix the issue that data race occurs when the `MergeLabels` function is called [#7535](https://github.com/tikv/pd/issues/7535) @[lhy1024](https://github.com/lhy1024)
- - (dup): release-7.1.4.md > Bug fixes> PD - Fix the issue that there is no output when the `evict-leader-scheduler` interface is called [#7672](https://github.com/tikv/pd/issues/7672) @[CabinfeverB](https://github.com/CabinfeverB)
- - (dup): release-7.5.1.md > Bug fixes> PD - Fix the issue that the PD monitoring item `learner-peer-count` does not synchronize the old value after a leader switch [#7728](https://github.com/tikv/pd/issues/7728) @[CabinfeverB](https://github.com/CabinfeverB)
- - (dup): release-7.1.4.md > Bug fixes> PD - Fix the memory leak issue that occurs when `watch etcd` is not turned off correctly [#7807](https://github.com/tikv/pd/issues/7807) @[rleungx](https://github.com/rleungx)
- - (dup): release-7.1.4.md > Bug fixes> PD - Fix the issue that some TSO logs do not print the error cause [#7496](https://github.com/tikv/pd/issues/7496) @[CabinfeverB](https://github.com/CabinfeverB)
+
++ PD
+
+ - Fix the issue that data race occurs when the `MergeLabels` function is called [#7535](https://github.com/tikv/pd/issues/7535) @[lhy1024](https://github.com/lhy1024)
+ - Fix the issue that there is no output when the `evict-leader-scheduler` interface is called [#7672](https://github.com/tikv/pd/issues/7672) @[CabinfeverB](https://github.com/CabinfeverB)
+ - Fix the issue that the PD monitoring item `learner-peer-count` does not synchronize the old value after a leader switch [#7728](https://github.com/tikv/pd/issues/7728) @[CabinfeverB](https://github.com/CabinfeverB)
+ - Fix the memory leak issue that occurs when `watch etcd` is not turned off correctly [#7807](https://github.com/tikv/pd/issues/7807) @[rleungx](https://github.com/rleungx)
+ - Fix the issue that some TSO logs do not print the error cause [#7496](https://github.com/tikv/pd/issues/7496) @[CabinfeverB](https://github.com/CabinfeverB)
- Fix the issue that there are unexpected negative monitoring metrics after restart [#4489](https://github.com/tikv/pd/issues/4489) @[lhy1024](https://github.com/lhy1024)
- Fix the issue that the Leader lease expires later than the log time [#7700](https://github.com/tikv/pd/issues/7700) @[CabinfeverB](https://github.com/CabinfeverB)
- - 修复 PD 客户端 TLS 相关的问题 [#7900](https://github.com/tikv/pd/issues/7900) [#7902](https://github.com/tikv/pd/issues/7902) [#7916](https://github.com/tikv/pd/issues/7916) @[CabinfeverB](https://github.com/CabinfeverB)
+ - Fix the issue that TiDB panics when TLS switches between TiDB (the PD client) and PD are inconsistent [#7900](https://github.com/tikv/pd/issues/7900) [#7902](https://github.com/tikv/pd/issues/7902) [#7916](https://github.com/tikv/pd/issues/7916) @[CabinfeverB](https://github.com/CabinfeverB)
- Fix the issue that Goroutine leaks when it is not closed properly [#7782](https://github.com/tikv/pd/issues/7782) @[HuSharp](https://github.com/HuSharp)
- Fix the issue that pd-ctl cannot remove a scheduler that contains special characters [#7798](https://github.com/tikv/pd/issues/7798) @[JmPotato](https://github.com/JmPotato)
- Fix the issue that the PD client might be blocked when obtaining TSO [#7864](https://github.com/tikv/pd/issues/7864) @[CabinfeverB](https://github.com/CabinfeverB)
-+ TiFlash
++ TiFlash
- - (dup): release-7.5.1.md > Bug fixes> TiFlash - Fix the issue that TiFlash might panic due to unstable network connections with PD during replica migration [#8323](https://github.com/pingcap/tiflash/issues/8323) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > Bug fixes> TiFlash - Fix the issue that the memory usage increases significantly due to slow queries [#8564](https://github.com/pingcap/tiflash/issues/8564) @[JinheLin](https://github.com/JinheLin)
- - (dup): release-7.5.1.md > Bug fixes> TiFlash - Fix the issue that removing and then re-adding TiFlash replicas might lead to data corruption in TiFlash [#8695](https://github.com/pingcap/tiflash/issues/8695) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > Bug fixes> TiFlash - Fix the issue that TiFlash replica data might be accidentally deleted after performing point-in-time recovery (PITR) or executing `FLASHBACK CLUSTER TO`, which might result in data anomalies [#8777](https://github.com/pingcap/tiflash/issues/8777) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > Bug fixes> TiFlash - Fix the issue that TiFlash panics after executing `ALTER TABLE ... MODIFY COLUMN ... NOT NULL`, which changes nullable columns to non-nullable [#8419](https://github.com/pingcap/tiflash/issues/8419) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - Fix the issue that TiFlash might panic due to unstable network connections with PD during replica migration [#8323](https://github.com/pingcap/tiflash/issues/8323) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - Fix the issue that the memory usage increases significantly due to slow queries [#8564](https://github.com/pingcap/tiflash/issues/8564) @[JinheLin](https://github.com/JinheLin)
+ - Fix the issue that removing and then re-adding TiFlash replicas might lead to data corruption in TiFlash [#8695](https://github.com/pingcap/tiflash/issues/8695) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - Fix the issue that TiFlash replica data might be accidentally deleted after performing point-in-time recovery (PITR) or executing `FLASHBACK CLUSTER TO`, which might result in data anomalies [#8777](https://github.com/pingcap/tiflash/issues/8777) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - Fix the issue that TiFlash panics after executing `ALTER TABLE ... MODIFY COLUMN ... NOT NULL`, which changes nullable columns to non-nullable [#8419](https://github.com/pingcap/tiflash/issues/8419) @[JaySon-Huang](https://github.com/JaySon-Huang)
- Fix the issue that in the disaggregated storage and compute architecture, queries might be permanently blocked after network isolation [#8806](https://github.com/pingcap/tiflash/issues/8806) @[JinheLin](https://github.com/JinheLin)
- Fix the issue that in the disaggregated storage and compute architecture, TiFlash might panic during shutdown [#8837](https://github.com/pingcap/tiflash/issues/8837) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - Fix the issue that TiFlash might crash due to data race in case of remote reads [#8685](https://github.com/pingcap/tiflash/issues/8685) @[solotzg](https://github.com/solotzg)
+ - Fix the issue that the `CAST(AS JSON)` function does not de-duplicate the JSON object key [#8712](https://github.com/pingcap/tiflash/issues/8712) @[SeaRise](https://github.com/SeaRise)
+ - Fix the issue that the `ENUM` column might cause TiFlash to crash during chunk encoding [#8674](https://github.com/pingcap/tiflash/issues/8674) @[yibin87](https://github.com/yibin87)
+ Tools
- + Backup & Restore (BR)
-
+ + Backup & Restore (BR)
+
- Fix the issue that the log backup checkpoint gets stuck when a Region is split or merged immediately after it becomes a leader [#16469](https://github.com/tikv/tikv/issues/16469) @[YuJuncen](https://github.com/YuJuncen)
- Fix the issue that TiKV panics when a full backup fails to find a peer in some extreme cases [#16394](https://github.com/tikv/tikv/issues/16394) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that log backup gets stuck after changing the TiKV IP address on the same node [#50445](https://github.com/pingcap/tidb/issues/50445) @[3pointer](https://github.com/3pointer)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that BR cannot retry when encountering an error while reading file content from S3 [#49942](https://github.com/pingcap/tidb/issues/49942) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that when resuming from a checkpoint after data restore fails, an error `the target cluster is not fresh` occurs [#50232](https://github.com/pingcap/tidb/issues/50232) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that stopping a log backup task causes TiDB to crash [#50839](https://github.com/pingcap/tidb/issues/50839) @[YuJuncen](https://github.com/YuJuncen)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that data restore is slowed down due to absence of a leader on a TiKV node [#50566](https://github.com/pingcap/tidb/issues/50566) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > Bug fixes> Tools> Backup & Restore (BR) - Fix the issue that full restore still requires the target cluster to be empty after the `--filter` option is specified [#51009](https://github.com/pingcap/tidb/issues/51009) @[3pointer](https://github.com/3pointer)
-
- + TiCDC
-
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that the file sequence number generated by the storage service might not increment correctly when using the storage sink [#10352](https://github.com/pingcap/tiflow/issues/10352) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that TiCDC returns the `ErrChangeFeedAlreadyExists` error when concurrently creating multiple changefeeds [#10430](https://github.com/pingcap/tiflow/issues/10430) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that after filtering out `add table partition` events is configured in `ignore-event`, TiCDC does not replicate other types of DML changes for related partitions to the downstream [#10524](https://github.com/pingcap/tiflow/issues/10524) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that the changefeed reports an error after `TRUNCATE PARTITION` is executed on the upstream table [#10522](https://github.com/pingcap/tiflow/issues/10522) @[sdojjy](https://github.com/sdojjy)
- - (dup): release-7.1.4.md > Bug fixes> Tools> TiCDC - Fix the issue that `snapshot lost caused by GC` is not reported in time when resuming a changefeed and the `checkpoint-ts` of the changefeed is smaller than the GC safepoint of TiDB [#10463](https://github.com/pingcap/tiflow/issues/10463) @[sdojjy](https://github.com/sdojjy)
- - (dup): release-7.1.4.md > Bug fixes> Tools> TiCDC - Fix the issue that TiCDC fails to validate `TIMESTAMP` type checksum due to time zone mismatch after data integrity validation for single-row data is enabled [#10573](https://github.com/pingcap/tiflow/issues/10573) @[3AceShowHand](https://github.com/3AceShowHand)
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that the Syncpoint table might be incorrectly replicated [#10576](https://github.com/pingcap/tiflow/issues/10576) @[asddongmen](https://github.com/asddongmen)
- - (dup): release-7.5.1.md > Bug fixes> Tools> TiCDC - Fix the issue that OAuth2.0, TLS, and mTLS cannot be enabled properly when using Apache Pulsar as the downstream [#10602](https://github.com/pingcap/tiflow/issues/10602) @[asddongmen](https://github.com/asddongmen)
+ - Fix the issue that log backup gets stuck after changing the TiKV IP address on the same node [#50445](https://github.com/pingcap/tidb/issues/50445) @[3pointer](https://github.com/3pointer)
+ - Fix the issue that BR cannot retry when encountering an error while reading file content from S3 [#49942](https://github.com/pingcap/tidb/issues/49942) @[Leavrth](https://github.com/Leavrth)
+ - Fix the issue that when resuming from a checkpoint after data restore fails, an error `the target cluster is not fresh` occurs [#50232](https://github.com/pingcap/tidb/issues/50232) @[Leavrth](https://github.com/Leavrth)
+ - Fix the issue that stopping a log backup task causes TiDB to crash [#50839](https://github.com/pingcap/tidb/issues/50839) @[YuJuncen](https://github.com/YuJuncen)
+ - Fix the issue that data restore is slowed down due to absence of a leader on a TiKV node [#50566](https://github.com/pingcap/tidb/issues/50566) @[Leavrth](https://github.com/Leavrth)
+ - Fix the issue that full restore still requires the target cluster to be empty after the `--filter` option is specified [#51009](https://github.com/pingcap/tidb/issues/51009) @[3pointer](https://github.com/3pointer)
+
+ + TiCDC
+
+ - Fix the issue that the file sequence number generated by the storage service might not increment correctly when using the storage sink [#10352](https://github.com/pingcap/tiflow/issues/10352) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - Fix the issue that TiCDC returns the `ErrChangeFeedAlreadyExists` error when concurrently creating multiple changefeeds [#10430](https://github.com/pingcap/tiflow/issues/10430) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - Fix the issue that after filtering out `add table partition` events is configured in `ignore-event`, TiCDC does not replicate other types of DML changes for related partitions to the downstream [#10524](https://github.com/pingcap/tiflow/issues/10524) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - Fix the issue that the changefeed reports an error after `TRUNCATE PARTITION` is executed on the upstream table [#10522](https://github.com/pingcap/tiflow/issues/10522) @[sdojjy](https://github.com/sdojjy)
+ - Fix the issue that `snapshot lost caused by GC` is not reported in time when resuming a changefeed and the `checkpoint-ts` of the changefeed is smaller than the GC safepoint of TiDB [#10463](https://github.com/pingcap/tiflow/issues/10463) @[sdojjy](https://github.com/sdojjy)
+ - Fix the issue that TiCDC fails to validate `TIMESTAMP` type checksum due to time zone mismatch after data integrity validation for single-row data is enabled [#10573](https://github.com/pingcap/tiflow/issues/10573) @[3AceShowHand](https://github.com/3AceShowHand)
+ - Fix the issue that the Syncpoint table might be incorrectly replicated [#10576](https://github.com/pingcap/tiflow/issues/10576) @[asddongmen](https://github.com/asddongmen)
+ - Fix the issue that OAuth2.0, TLS, and mTLS cannot be enabled properly when using Apache Pulsar as the downstream [#10602](https://github.com/pingcap/tiflow/issues/10602) @[asddongmen](https://github.com/asddongmen)
- Fix the issue that a changefeed might get stuck when TiKV upgrades, restarts, or evicts a leader [#10584](https://github.com/pingcap/tiflow/issues/10584) @[asddongmen](https://github.com/asddongmen)
- Fix the issue that data is written to a wrong CSV file due to wrong BarrierTS in scenarios where DDL statements are executed frequently [#10668](https://github.com/pingcap/tiflow/issues/10668) @[lidezhu](https://github.com/lidezhu)
- Fix the issue that data race in the KV client causes TiCDC to panic [#10718](https://github.com/pingcap/tiflow/issues/10718) @[asddongmen](https://github.com/asddongmen)
@@ -551,8 +571,8 @@ Quick access: [Quick start](https://docs.pingcap.com/tidb/v8.0/quick-start-with-
+ TiDB Lightning
- Fix the performance regression issue caused by checking TiKV space [#43636](https://github.com/pingcap/tidb/issues/43636) @[lance6716](https://github.com/lance6716)
- - (dup): release-7.1.4.md > Bug fixes> Tools> TiDB Lightning - Fix the issue that TiDB Lightning reports an error when encountering invalid symbolic link files during file scanning [#49423](https://github.com/pingcap/tidb/issues/49423) @[lance6716](https://github.com/lance6716)
- - (dup): release-7.1.4.md > Bug fixes> Tools> TiDB Lightning - Fix the issue that TiDB Lightning fails to correctly parse date values containing `0` when `NO_ZERO_IN_DATE` is not included in `sql_mode` [#50757](https://github.com/pingcap/tidb/issues/50757) @[GMHDBJD](https://github.com/GMHDBJD)
+ - Fix the issue that TiDB Lightning reports an error when encountering invalid symbolic link files during file scanning [#49423](https://github.com/pingcap/tidb/issues/49423) @[lance6716](https://github.com/lance6716)
+ - Fix the issue that TiDB Lightning fails to correctly parse date values containing `0` when `NO_ZERO_IN_DATE` is not included in `sql_mode` [#50757](https://github.com/pingcap/tidb/issues/50757) @[GMHDBJD](https://github.com/GMHDBJD)
## Contributors
diff --git a/markdown-pages/zh/tidb/release-8.0/releases/release-8.0.0.md b/markdown-pages/zh/tidb/release-8.0/releases/release-8.0.0.md
index 7c804a27..1209d7a3 100644
--- a/markdown-pages/zh/tidb/release-8.0/releases/release-8.0.0.md
+++ b/markdown-pages/zh/tidb/release-8.0/releases/release-8.0.0.md
@@ -47,7 +47,7 @@ TiDB 版本：8.0.0
| 数据库管理与可观测性 |
支持观测索引使用情况 |
- TiDB v8.0.0 引入 INFORMATION_SCHEMA.TIDB_INDEX_USAGE 表和 sys.schema_unused_index 视图，以提供索引的使用统计信息。该功能有助于用户评估所有索引的重要性并优化索引设计。 |
+ 正确的索引设计是提升数据库性能的重要前提。TiDB v8.0.0 引入内存表 INFORMATION_SCHEMA.TIDB_INDEX_USAGE 和视图 sys.schema_unused_index ，用于记录索引的使用情况。该功能有助于用户评估数据库中索引的效率并优化索引设计。 |
| 数据迁移 |
@@ -65,7 +65,7 @@ TiDB 版本：8.0.0
### 可扩展性
-- PD 支持微服务模式（实验特性）[#5766](https://github.com/tikv/pd/issues/5766) @[binshi-bing](https://github.com/binshi-bing) **tw@qiancai**
+- PD 支持微服务模式（实验特性）[#5766](https://github.com/tikv/pd/issues/5766) @[binshi-bing](https://github.com/binshi-bing)
从 v8.0.0 开始，PD 支持微服务模式。该模式可将 PD 的时间戳分配和集群调度功能拆分为以下微服务单独部署，从而实现 PD 的性能扩展，解决大规模集群下 PD 的性能瓶颈问题。
@@ -78,39 +78,39 @@ TiDB 版本：8.0.0
更多信息，请参考[用户文档](/pd-microservices.md)。
-* 增强 Titan 引擎的易用性 [#16245](https://github.com/tikv/tikv/issues/16245) @[Connor1996](https://github.com/Connor1996) **tw@qiancai**
+* 增强 Titan 引擎的易用性 [#16245](https://github.com/tikv/tikv/issues/16245) @[Connor1996](https://github.com/Connor1996)
- - 默认启用 Titan Blob 文件和 RocksDB Block 文件的共享缓存（[`shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache-tidb-从-v800-版本开始引入) 默认为 `true`），无需再单独配置 [`blob-cache-size`](/tikv-configuration-file.md#blob-cache-size)。
+ - 默认启用 Titan Blob 文件和 RocksDB Block 文件的共享缓存（[`shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache从-v800-版本开始引入) 默认为 `true`），无需再单独配置 [`blob-cache-size`](/tikv-configuration-file.md#blob-cache-size)。
- 支持动态修改 [`min-blob-size`](/tikv-configuration-file.md#min-blob-size)、[`blob-file-compression`](/tikv-configuration-file.md#blob-file-compression)、[`discardable-ratio`](/tikv-configuration-file.md#min-blob-size)，以提升使用 Titan 引擎时的性能和灵活性。
更多信息，请参考[用户文档](/storage-engine/titan-configuration.md)。
-
+
### 性能
-* BR 快照恢复速度提升 GA [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer) @[Leavrth](https://github.com/Leavrth) **tw@qiancai**
+* BR 快照恢复速度提升 GA [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer) @[Leavrth](https://github.com/Leavrth)
+
+ 从 TiDB v8.0.0 版本起，BR 快照恢复提速功能正式发布并默认启用。通过采用粗粒度打散 Region 算法、批量创建库表、降低 SST 文件下载和 Ingest 操作之间的相互影响、加速表统计信息恢复等改进措施，快照恢复的速度有大幅提升。在实际案例中，单个 TiKV 节点的数据恢复速度稳定在 1.2 GiB/s，并且能够在 1 小时内完成对 100 TiB 数据的恢复。
+
+ 这意味着即使在高负载环境下，BR 工具也能够充分利用每个 TiKV 节点的资源，显著减少数据库恢复时间，增强数据库的可用性和可靠性，减少因数据丢失或系统故障引起的停机时间和业务损失。需要注意的是，恢复速度的提升是因为使用了大量的 goroutine 来并行工作，会有比较大的内存消耗，特别是在表或者 Region 数很多的时候，推荐使用内存规格较高的机器来运行 BR 的客户端。如果机器的内存规格较小，建议改用细粒度的 Region 分裂打散策略。此外，因为粗粒度打散 Region 算法会占用大量的外部存储带宽，请避免因为外部带宽不足导致的对其他业务的影响。
- TiDB v8.0.0 版本正式发布并默认启用新的快照恢复算法，通过采用粗粒度打散 Region 算法、批量创建库表、降低 SST 文件下载和 Ingest 操作之间的相互影响、加速表统计信息恢复等改进措施，快照恢复的速度有大幅提升。在实际案例中，单个 TiKV 节点的数据恢复速度稳定在 1.2 GiB/s，并且能够在 1 小时内完成对 100 TiB 数据的恢复。
-
- 这意味着即使在高负载环境下，BR 工具也能够充分利用每个 TiKV 节点的资源，显著减少数据库恢复时间，增强数据库的可用性和可靠性，减少因数据丢失或系统故障引起的停机时间和业务损失。需要注意的是，恢复速度的提升是因为使用了大量的 goroutine 来并行工作，会有比较大的内存消耗，特别是在表或者 Region 数很多的时候，推荐使用内存规格较高的机器来运行 BR 的客户端。如果机器的内存规格较小，建议改用细粒度的 Region 分裂打散策略。
-
更多信息，请参考[用户文档](/br/br-snapshot-guide.md#恢复快照备份数据)。
-
-* 新增支持下推以下函数到 TiFlash [#50975](https://github.com/pingcap/tidb/issues/50975) [#50485](https://github.com/pingcap/tidb/issues/50485) @[yibin87](https://github.com/yibin87) @[windtalker](https://github.com/windtalker) **tw@Oreoxmt**
+
+* 新增支持下推以下函数到 TiFlash [#50975](https://github.com/pingcap/tidb/issues/50975) [#50485](https://github.com/pingcap/tidb/issues/50485) @[yibin87](https://github.com/yibin87) @[windtalker](https://github.com/windtalker)
* `CAST(DECIMAL AS DOUBLE)`
* `POWER()`
更多信息，请参考[用户文档](/tiflash/tiflash-supported-pushdown-calculations.md)。
-* TiDB 的并发 HashAgg 算法支持数据落盘（实验特性）[#35637](https://github.com/pingcap/tidb/issues/35637) @[xzhangxian1008](https://github.com/xzhangxian1008) **tw@qiancai**
+* TiDB 的并发 HashAgg 算法支持数据落盘（实验特性）[#35637](https://github.com/pingcap/tidb/issues/35637) @[xzhangxian1008](https://github.com/xzhangxian1008)
在之前的 TiDB 版本中，HashAgg 算子的并发算法不支持数据落盘。当 SQL 语句的执行计划包含并发的 HashAgg 算子时，该 SQL 语句的所有数据都只能在内存中进行处理。这导致内存需要处理大量数据，当超过内存限制时，TiDB 只能选择非并发 HashAgg 算法，无法通过并发提升性能。
- 在 v8.0.0 中，TiDB 的并发 HashAgg 算法支持数据落盘。在任意并发条件下，HashAgg 算子都可以根据内存使用情况自动触发数据落盘，从而兼顾性能和数据处理量。目前，该功能作为实验特性，引入变量 `tidb_enable_concurrent_hashagg_spill` 控制是否启用支持落盘的并发 HashAgg 算法。当该变量为 `ON` 时，代表启用。该变量将在功能正式发布时废弃。
+ 在 v8.0.0 中，TiDB 的并发 HashAgg 算法支持数据落盘。在任意并发条件下，HashAgg 算子都可以根据内存使用情况自动触发数据落盘，从而兼顾性能和数据处理量。目前，该功能作为实验特性，引入变量 `tidb_enable_concurrent_hashagg_spill` 控制是否启用支持落盘的并发 HashAgg 算法。当该变量为 `ON` 时，代表启用。该变量将在功能正式发布后废弃。
更多信息，请参考[用户文档](/system-variables.md#tidb_enable_concurrent_hashagg_spill-从-v800-版本开始引入)。
-* 自动统计信息收集引入优先级队列 [#50132](https://github.com/pingcap/tidb/issues/50132) @[hi-rustin](https://github.com/hi-rustin) **tw@hfxsd**
+* 自动统计信息收集引入优先级队列 [#50132](https://github.com/pingcap/tidb/issues/50132) @[hi-rustin](https://github.com/hi-rustin)
维持优化器统计信息的时效性是稳定数据库性能的关键，绝大多数用户依赖 TiDB 提供的[自动统计信息收集](/statistics.md#自动更新)来保持统计信息的更新。自动统计信息收集轮询所有对象的统计信息状态，并把健康度不足的对象加入队列，逐个收集并更新。在之前的版本中，这些对象的收集顺序是随机的，可能导致更需要更新的对象等待时间过长，从而引发潜在的数据库性能回退。
@@ -118,7 +118,7 @@ TiDB 版本：8.0.0
更多信息，请参考[用户文档](/system-variables.md#tidb_enable_auto_analyze_priority_queue-从-v800-版本开始引入)。
-* 解除执行计划缓存的部分限制 [#49161](https://github.com/pingcap/tidb/pull/49161) @[mjonss](https://github.com/mjonss) @[qw4990](https://github.com/qw4990) **tw@hfxsd**
+* 解除执行计划缓存的部分限制 [#49161](https://github.com/pingcap/tidb/pull/49161) @[mjonss](https://github.com/mjonss) @[qw4990](https://github.com/qw4990)
TiDB 支持[执行计划缓存](/sql-prepared-plan-cache.md)，能够有效降低交易类业务系统的处理时延，是提升性能的重要手段。在 v8.0.0 中，TiDB 解除了执行计划缓存的几个限制，含有以下内容的执行计划均能够被缓存：
@@ -129,7 +129,7 @@ TiDB 版本：8.0.0
更多信息，请参考[用户文档](/sql-prepared-plan-cache.md)。
-* 优化器增强对多值索引的支持 [#47759](https://github.com/pingcap/tidb/issues/47759) [#46539](https://github.com/pingcap/tidb/issues/46539) @[Arenatlx](https://github.com/Arenatlx) @[time-and-fate](https://github.com/time-and-fate) **tw@hfxsd**
+* 优化器增强对多值索引的支持 [#47759](https://github.com/pingcap/tidb/issues/47759) [#46539](https://github.com/pingcap/tidb/issues/46539) @[Arenatlx](https://github.com/Arenatlx) @[time-and-fate](https://github.com/time-and-fate)
TiDB 自 v6.6.0 开始引入[多值索引](/sql-statements/sql-statement-create-index.md#多值索引)，提升对 JSON 数据类型的检索性能。在 v8.0.0 中，优化器增强了对多值索引的支持能力，使其在复杂场景下能够正确识别和利用多值索引来优化查询。
@@ -138,7 +138,7 @@ TiDB 版本：8.0.0
更多信息，请参考[用户文档](/sql-statements/sql-statement-create-index.md#多值索引)。
-* 支持设置低精度 TSO 的更新间隔 [#51081](https://github.com/pingcap/tidb/issues/51081) @[Tema](https://github.com/Tema) **tw@hfxsd**
+* 支持设置低精度 TSO 的更新间隔 [#51081](https://github.com/pingcap/tidb/issues/51081) @[Tema](https://github.com/Tema)
TiDB 的[低精度 TSO 功能](/system-variables.md#tidb_low_resolution_tso)使用定期更新的 TSO 作为事务时间戳。在可以容忍读到旧数据的情况下，该功能通过牺牲一定的实时性，降低小的只读事务获取 TSO 的开销，从而提升高并发读的能力。
@@ -148,22 +148,22 @@ TiDB 版本：8.0.0
### 稳定性
-* 支持根据 LRU 算法缓存所需的 schema 信息，以减少 TiDB server 的内存消耗（实验特性）[#50959](https://github.com/pingcap/tidb/issues/50959) @[gmhdbjd](https://github.com/gmhdbjd) **tw@hfxsd**
+* 支持根据 LRU 算法缓存所需的 schema 信息，以减少 TiDB server 的内存消耗（实验特性）[#50959](https://github.com/pingcap/tidb/issues/50959) @[gmhdbjd](https://github.com/gmhdbjd)
在 v8.0.0 之前，每个 TiDB 节点都会缓存所有表的 schema 信息。在表数量较多的情况下，例如高达几十万张表，仅缓存这些表的 schema 信息就会占用大量内存。
-
+
从 v8.0.0 开始，TiDB 引入 [`tidb_schema_cache_size`](/system-variables.md#tidb_schema_cache_size-从-v800-版本开始引入) 系统变量，允许设置缓存 schema 信息所能使用的内存上限，从而避免占用过多的内存。开启该功能后，TiDB 将使用 Least Recently Used (LRU) 算法缓存所需的表，有效降低 schema 信息占用的内存。
更多信息，请参考[用户文档](/system-variables.md#tidb_schema_cache_size-从-v800-版本开始引入)。
### 高可用
-* 代理组件 TiProxy 成为正式功能 (GA) [#413](https://github.com/pingcap/tiproxy/issues/413) @[djshow832](https://github.com/djshow832) @[xhebox](https://github.com/xhebox) **tw@Oreoxmt**
+* 代理组件 TiProxy 成为正式功能 (GA) [#413](https://github.com/pingcap/tiproxy/issues/413) @[djshow832](https://github.com/djshow832) @[xhebox](https://github.com/xhebox)
TiDB v7.6.0 引入了代理组件 TiProxy 作为实验特性。TiProxy 是 TiDB 的官方代理组件，位于客户端和 TiDB server 之间，为 TiDB 提供负载均衡、连接保持功能，让 TiDB 集群的负载更加均衡，并在维护操作期间不影响用户对数据库的连接访问。
-
+
在 v8.0.0 中，TiProxy 成为正式功能，完善了签名证书自动生成、监控等功能。
-
+
TiProxy 的应用场景如下：
* 在 TiDB 集群进行滚动重启、滚动升级、缩容等维护操作时，TiDB server 会发生变动，导致客户端与发生变化的 TiDB server 的连接中断。通过使用 TiProxy，可以在这些维护操作过程中平滑地将连接迁移至其他 TiDB server，从而让客户端不受影响。
@@ -175,7 +175,7 @@ TiDB 版本：8.0.0
### SQL 功能
-* 支持处理大量数据的 DML 类型（实验特性）[#50215](https://github.com/pingcap/tidb/issues/50215) @[ekexium](https://github.com/ekexium) **tw@Oreoxmt**
+* 支持处理大量数据的 DML 类型（实验特性）[#50215](https://github.com/pingcap/tidb/issues/50215) @[ekexium](https://github.com/ekexium)
在 TiDB v8.0.0 之前，所有事务数据在提交之前均存储在内存中。当处理大量数据时，事务所需的内存成为限制 TiDB 处理事务大小的瓶颈。虽然 TiDB 非事务 DML 功能通过拆分 SQL 语句的方式尝试解决事务大小限制，但该功能存在多种限制，在实际应用中的体验并不理想。
@@ -185,13 +185,13 @@ TiDB 版本：8.0.0
更多信息，请参考[用户文档](/system-variables.md#tidb_dml_type-从-v800-版本开始引入)。
-* 支持在 TiDB 建表时使用更多的表达式设置列的默认值（实验特性）[#50936](https://github.com/pingcap/tidb/issues/50936) @[zimulala](https://github.com/zimulala) **tw@hfxsd**
+* 支持在 TiDB 建表时使用更多的表达式设置列的默认值（实验特性）[#50936](https://github.com/pingcap/tidb/issues/50936) @[zimulala](https://github.com/zimulala)
在 v8.0.0 之前，建表时指定列的默认值仅限于固定的字符串、数字和日期。从 v8.0.0 开始，TiDB 支持使用部分表达式作为列的默认值，例如将列的默认值设置为 `UUID()`，从而满足多样化的业务需求。
更多信息，请参考[用户文档](/data-type-default-values.md#表达式默认值)。
-* 支持系统变量 `div_precision_increment` [#51501](https://github.com/pingcap/tidb/issues/51501) @[yibin87](https://github.com/yibin87) **tw@hfxsd**
+* 支持系统变量 `div_precision_increment` [#51501](https://github.com/pingcap/tidb/issues/51501) @[yibin87](https://github.com/yibin87)
MySQL 8.0 增加了变量 `div_precision_increment`，用于指定除法 `/` 运算结果增加的小数位数。在 v8.0.0 之前，TiDB 不支持该变量，而是按照 4 位小数进行除法计算。从 v8.0.0 开始，TiDB 支持该变量，你可以根据需要指定除法运算结果增加的小数位数。
@@ -199,33 +199,33 @@ TiDB 版本：8.0.0
### 数据库管理
-* PITR 支持 Amazon S3 对象锁定 [#51184](https://github.com/pingcap/tidb/issues/51184) @[RidRisR](https://github.com/RidRisR) **tw@lilin90**
+* PITR 支持 Amazon S3 对象锁定 [#51184](https://github.com/pingcap/tidb/issues/51184) @[RidRisR](https://github.com/RidRisR)
Amazon S3 对象锁定功能支持用户通过设置数据留存期，有效防止备份数据在指定时间内被意外或故意删除，提升了数据的安全性和完整性。从 v6.3.0 起，BR 为快照备份引入了对 Amazon S3 对象锁定功能的支持，为全量备份增加了额外的安全性保障。从 v8.0.0 起，PITR 也引入了对 Amazon S3 对象锁定功能的支持，无论是全量备份还是日志数据备份，都可以通过对象锁定功能提供更可靠的数据保护，进一步加强了数据备份和恢复的安全性，并满足了监管方面的需求。
-
+
更多信息，请参考[用户文档](/br/backup-and-restore-storages.md#存储服务其他功能支持)。
-
-* 支持在会话级将不可见索引 (Invisible Indexes) 调整为可见 [#50653](https://github.com/pingcap/tidb/issues/50653) @[hawkingrei](https://github.com/hawkingrei) **tw@Oreoxmt**
- 在优化器选择索引以优化查询执行时，默认情况下不会选择[不可见索引](/sql-statements/sql-statement-create-index.md#不可见索引)。这一机制通常用于在评估是否删除某个索引之前。如果担心删除索引可能导致性能下降，可以先将索引设置为不可见，以便在必要时快速将其恢复为可见。
-
- 从 v8.0.0 开始，你可以将会话级系统变量 [`tidb_opt_use_invisible_indexes`](/system-variables.md#) 设置为 `ON`，让当前会话识别并使用不可见索引。利用这个功能，在添加新索引并希望测试其效果时，可以先将索引创建为不可见索引，然后通过修改该系统变量在当前会话中进行测试新索引的性能，而不影响其他会话。这一改进提高了进行性能调优的安全性，并有助于增强生产数据库的稳定性。
+* 支持在会话级将不可见索引 (Invisible Indexes) 调整为可见 [#50653](https://github.com/pingcap/tidb/issues/50653) @[hawkingrei](https://github.com/hawkingrei)
+
+ 在优化器选择索引时，默认情况下不会选择[不可见索引](/sql-statements/sql-statement-create-index.md#不可见索引)。这一机制通常用于在评估是否删除某个索引之前。如果担心删除索引可能导致性能下降，可以先将索引设置为不可见，以便在必要时快速将其恢复为可见。
+
+ 从 v8.0.0 开始，你可以将会话级系统变量 [`tidb_opt_use_invisible_indexes`](/system-variables.md#tidb_opt_use_invisible_indexes-从-v800-版本开始引入) 设置为 `ON`，让当前会话识别并使用不可见索引。利用这个功能，在添加新索引并希望测试其效果时，可以先将索引创建为不可见索引，然后通过修改该系统变量在当前会话中测试新索引的性能，而不影响其他会话。这一改进提高了性能调优的安全性，并有助于增强生产数据库的稳定性。
更多信息，请参考[用户文档](/sql-statements/sql-statement-create-index.md#不可见索引)。
-* 支持将 general log 写入独立文件 [#51248](https://github.com/pingcap/tidb/issues/51248) @[Defined2014](https://github.com/Defined2014) **tw@hfxsd**
+* 支持将 general log 写入独立文件 [#51248](https://github.com/pingcap/tidb/issues/51248) @[Defined2014](https://github.com/Defined2014)
general log 是与 MySQL 兼容的功能，开启后能够记录数据库执行的所有 SQL 语句，为问题诊断提供依据。TiDB 也支持此功能，你可以通过设置变量 [`tidb_general_log`](/system-variables.md#tidb_general_log) 开启该功能。在之前的版本中，general log 的内容只能和其他信息一起写入实例日志中，这对于需要长期保存日志的用户来说并不方便。
从 v8.0.0 开始，你可以通过配置项 [`log.general-log-file`](/tidb-configuration-file.md#general-log-file-从-v800-版本开始引入) 指定一个文件名，将 general log 单独写入该文件。和实例日志一样，general log 也遵循日志的轮询和保存策略。
-
+
另外，为了减少历史日志文件所占用的磁盘空间，TiDB 在 v8.0.0 支持了原生的日志压缩选项。你可以将配置项 [`log.file.compression`](/tidb-configuration-file.md#compression-从-v800-版本开始引入) 设置为 `gzip`，使得轮询出的历史日志自动以 [`gzip`](https://www.gzip.org/) 格式压缩。
更多信息，请参考[用户文档](/tidb-configuration-file.md#general-log-file-从-v800-版本开始引入)。
-
+
### 可观测性
-* 支持观测索引使用情况 [#49830](https://github.com/pingcap/tidb/issues/49830) @[YangKeao](https://github.com/YangKeao) **tw@Oreoxmt**
+* 支持观测索引使用情况 [#49830](https://github.com/pingcap/tidb/issues/49830) @[YangKeao](https://github.com/YangKeao)
正确的索引设计是提升数据库性能的重要前提。TiDB v8.0.0 新增内存表 [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md)，用于记录当前 TiDB 节点中所有索引的访问统计信息，包括：
@@ -242,15 +242,15 @@ TiDB 版本：8.0.0
### 安全
-* TiKV 静态加密支持 Google [Key Management Service (Cloud KMS)](https://cloud.google.com/docs/security/key-management-deep-dive?hl=zh-cn)（实验特性）[#8906](https://github.com/tikv/tikv/issues/8906) @[glorv](https://github.com/glorv) **tw@qiancai**
+* TiKV 静态加密支持 Google [Key Management Service (Cloud KMS)](https://cloud.google.com/docs/security/key-management-deep-dive?hl=zh-cn)（实验特性）[#8906](https://github.com/tikv/tikv/issues/8906) @[glorv](https://github.com/glorv)
TiKV 通过静态加密功能对存储的数据进行加密，以确保数据的安全性。静态加密的安全核心点在于密钥管理。从 v8.0.0 起，你可以通过 Google Cloud KMS 管理 TiKV 的主密钥，构建基于 Cloud KMS 的静态加密能力，从而提高用户数据的安全性。
-
+
要启用基于 Google Cloud KMS 的静态加密，你需要在 Google Cloud 上创建一个密钥，然后在 TiKV 配置文件中添加 `[security.encryption.master-key]` 部分的配置。
更多信息，请参考[用户文档](/encryption-at-rest.md#tikv-静态加密)。
-* 增强 TiDB 日志脱敏 [#51306](https://github.com/pingcap/tidb/issues/51306) @[xhebox](https://github.com/xhebox) **tw@hfxsd**
+* 增强 TiDB 日志脱敏 [#51306](https://github.com/pingcap/tidb/issues/51306) @[xhebox](https://github.com/xhebox)
TiDB 日志脱敏增强是通过对日志文件中的 SQL 文本信息进行标记，支持在查看时安全展示敏感数据。你可以控制是否对日志信息进行脱敏，以实现在不同场景下安全使用 TiDB 日志，提升了使用日志脱敏能力的安全性和灵活性。要使用此功能，可以将系统变量 `tidb_redact_log` 的值设置为 `MARKER`，此时 TiDB 的运行日志中的 SQL 文本会被标记，查看时将基于标记进行数据的安全展示，从而保护日志信息。
@@ -258,49 +258,49 @@ TiDB 版本：8.0.0
### 数据迁移
-* TiCDC 支持 Simple 协议 [#9898](https://github.com/pingcap/tiflow/issues/9898) @[3AceShowHand](https://github.com/3AceShowHand) **tw@lilin90**
+* TiCDC 支持 Simple 协议 [#9898](https://github.com/pingcap/tiflow/issues/9898) @[3AceShowHand](https://github.com/3AceShowHand)
TiCDC 支持了新的 Simple 消息协议，该协议通过在 DDL 和 BOOTSTRAP 事件中嵌入表的 schema 信息，实现了对 schema 信息的动态追踪 (in-band schema tracking)。
更多信息，请参考[用户文档](/ticdc/ticdc-simple-protocol.md)。
-* TiCDC 支持 Debezium 协议 [#1799](https://github.com/pingcap/tiflow/issues/1799) @[breezewish](https://github.com/breezewish) **tw@lilin90**
+* TiCDC 支持 Debezium 协议 [#1799](https://github.com/pingcap/tiflow/issues/1799) @[breezewish](https://github.com/breezewish)
通过 Debezium 协议，TiCDC 可以生成 Debezium 格式的数据变更事件，并将这些事件发送到 Kafka sink。这有助于为当前使用 Debezium 从 MySQL 拉取数据进行下游处理的用户简化从 MySQL 迁移到 TiDB 的过程。
更多信息，请参考[用户文档](/ticdc/ticdc-debezium.md)。
-* DM 支持使用用户提供的密钥对源数据库和目标数据库的密码进行加密和解密 [#9492](https://github.com/pingcap/tiflow/issues/9492) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
+* DM 支持使用用户提供的密钥对源数据库和目标数据库的密码进行加密和解密 [#9492](https://github.com/pingcap/tiflow/issues/9492) @[D3Hunter](https://github.com/D3Hunter)
在之前的版本中，DM 使用了一个内置的固定秘钥，安全性相对较低。从 v8.0.0 开始，你可以上传并指定一个密钥文件，用于对上下游数据库的密码进行加密和解密操作。此外，你还可以按需替换秘钥文件，以提升数据的安全性。
- 更多信息，请参考[用户文档](dm/dm-customized-secret-key.md)。
+ 更多信息，请参考[用户文档](/dm/dm-customized-secret-key.md)。
-* 支持 `IMPORT INTO ... FROM SELECT` 语法（实验特性），增强 `IMPORT INTO` 功能 [#49883](https://github.com/pingcap/tidb/issues/49883) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
+* 支持 `IMPORT INTO ... FROM SELECT` 语法（实验特性），增强 `IMPORT INTO` 功能 [#49883](https://github.com/pingcap/tidb/issues/49883) @[D3Hunter](https://github.com/D3Hunter)
在之前的 TiDB 版本中，将查询结果导入目标表只能通过 `INSERT INTO ... SELECT` 语句，但该语句在一些大数据量的场景中的导入效率较低。从 v8.0.0 开始，TiDB 新增支持通过 `IMPORT INTO ... FROM SELECT` 将 `SELECT` 的查询结果导入到一张空的 TiDB 目标表中，其性能最高可达 `INSERT INTO ... SELECT` 的 8 倍，可以大幅缩短导入所需的时间。
-
+
此外，你还可以通过 `IMPORT INTO ... FROM SELECT` 导入使用 [`AS OF TIMESTAMP`](/as-of-timestamp.md) 查询的历史数据。
- 更多信息，请参考[用户文档](sql-statements/sql-statement-import-into.md)。
-
-* TiDB Lightning 简化冲突处理策略，同时支持以 `replace` 方式处理冲突数据（实验特性）[#51036](https://github.com/pingcap/tidb/issues/51036) @[lyzx2001](https://github.com/lyzx2001) **tw@qiancai**
+ 更多信息，请参考[用户文档](/sql-statements/sql-statement-import-into.md)。
+
+* TiDB Lightning 简化冲突处理策略，同时支持以 `replace` 方式处理冲突数据（实验特性）[#51036](https://github.com/pingcap/tidb/issues/51036) @[lyzx2001](https://github.com/lyzx2001)
在之前的版本中，TiDB Lightning 逻辑导入模式有[一套数据冲突处理策略](/tidb-lightning/tidb-lightning-logical-import-mode-usage.md#冲突数据检测)，而物理导入模式有[两套数据冲突处理策略](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#冲突数据检测)，不易理解和配置。
-
- 从 v8.0.0 开始，TiDB Lightning 废弃了物理导入模式下的[旧版冲突检测](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#旧版冲突检测从-v800-开始已被废弃)策略，支持通过 [`conflict.strategy`](tidb-lightning/tidb-lightning-configuration.md) 参数统一控制逻辑导入和物理导入模式的冲突检测策略，并简化了该参数的配置。此外，在物理导入模式下，当导入遇到主键或唯一键冲突的数据时，`replace` 策略支持保留最新的数据、覆盖旧的数据。
- 更多信息，请参考[用户文档](tidb-lightning/tidb-lightning-configuration.md)。
-
-* 全局排序成为正式功能 (GA)，可显著提升 `IMPORT INTO` 任务的导入性能和稳定性 [#45719](https://github.com/pingcap/tidb/issues/45719) @[lance6716](https://github.com/lance6716) **tw@qiancai**
+ 从 v8.0.0 开始，TiDB Lightning 废弃了物理导入模式下的[旧版冲突检测](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#旧版冲突检测从-v800-开始已被废弃)策略，支持通过 [`conflict.strategy`](/tidb-lightning/tidb-lightning-configuration.md) 参数统一控制逻辑导入和物理导入模式的冲突检测策略，并简化了该参数的配置。此外，在物理导入模式下，当导入遇到主键或唯一键冲突的数据时，`replace` 策略支持保留最新的数据、覆盖旧的数据。
+
+ 更多信息，请参考[用户文档](/tidb-lightning/tidb-lightning-configuration.md)。
+
+* 全局排序成为正式功能 (GA)，可显著提升 `IMPORT INTO` 任务的导入性能和稳定性 [#45719](https://github.com/pingcap/tidb/issues/45719) @[lance6716](https://github.com/lance6716)
在 v7.4.0 以前，当使用[分布式执行框架](/tidb-distributed-execution-framework.md)执行 `IMPORT INTO` 任务时，由于本地存储空间有限，TiDB 只能对部分数据进行局部排序后再导入到 TiKV。这导致了导入到 TiKV 的数据存在较多的重叠，需要 TiKV 在导入过程中执行额外的 compaction 操作，影响了 TiKV 的性能和稳定性。
随着 v7.4.0 引入全局排序实验特性，TiDB 支持将需要导入的数据暂时存储在外部存储（如 Amazon S3）中进行全局排序后再导入到 TiKV 中，使 TiKV 无需在导入过程中执行 compaction 操作。全局排序在 v8.0.0 成为正式功能 (GA)，可以降低 TiKV 对资源的额外消耗，显著提升 `IMPORT INTO` 的性能和稳定性。启用全局排序后，单个 `IMPORT INTO` 任务支持导入 40 TiB 以内的数据。
- 更多信息，请参考[用户文档](/tidb-global-sort.md)。
+ 更多信息，请参考[用户文档](/tidb-global-sort.md)。
-## 兼容性变更
+## 兼容性变更
> **注意：**
>
@@ -312,11 +312,11 @@ TiDB 版本：8.0.0
### 行为变更
-* 在之前版本中，启用添加索引加速功能 (`tidb_ddl_enable_fast_reorg = ON`) 后，编码后的索引键值 ingest 到 TiKV 的过程使用了固定的并发数 (`16`)，并未根据下游 TiKV 的处理能力进行动态调整。从 v8.0.0 开始，支持使用 [`tidb_ddl_reorg_worker_cnt`](/system-variables.md#tidb_ddl_reorg_worker_cnt-从-v800-版本开始引入) 设置并发数。该变量默认值为 `4`，相比之前的默认值 `16`，在 ingest 索引键值对时性能可能会有所下降。你可以根据集群的负载按需调整该参数。**tw@hfxsd**
+* 在之前版本中，启用添加索引加速功能 (`tidb_ddl_enable_fast_reorg = ON`) 后，编码后的索引键值 ingest 到 TiKV 的过程使用了固定的并发数 (`16`)，并未根据下游 TiKV 的处理能力进行动态调整。从 v8.0.0 开始，支持使用 [`tidb_ddl_reorg_worker_cnt`](/system-variables.md#tidb_ddl_reorg_worker_cnt) 设置并发数。该变量默认值为 `4`，相比之前的默认值 `16`，在 ingest 索引键值对时性能可能会有所下降。你可以根据集群的负载按需调整该参数。
### MySQL 兼容性
-* `KEY` 分区类型支持分区字段列表为空的语句，具体行为和 MySQL 保持一致。**tw@hfxsd**
+* `KEY` 分区类型支持分区字段列表为空的语句，具体行为和 MySQL 保持一致。
### 系统变量
@@ -345,40 +345,40 @@ TiDB 版本：8.0.0
| TiDB | [`log.file.compression`](/tidb-configuration-file.md#compression-从-v800-版本开始引入) | 新增 | 指定轮询日志的压缩格式。默认为空，即不压缩轮询日志。 |
| TiDB | [`log.general-log-file`](/tidb-configuration-file.md#general-log-file-从-v800-版本开始引入) | 新增 | 指定 general log 的保存文件。默认为空，general log 将会写入实例文件。 |
| TiDB | [`tikv-client.enable-replica-selector-v2`](/tidb-configuration-file.md#enable-replica-selector-v2-从-v800-版本开始引入) | 新增 | 控制给 TiKV 发送 RPC 请求时，是否使用新版本的 Region 副本选择器。默认值为 `true`。 |
-| TiKV | [`log-backup.initial-scan-rate-limit`](/system-variables.md#initial-scan-rate-limit-从-v620-版本开始引入) | 修改 | 增加了最小值为 `1MiB` 的限制。 |
+| TiKV | [`log-backup.initial-scan-rate-limit`](/tikv-configuration-file.md#initial-scan-rate-limit-从-v620-版本开始引入) | 修改 | 增加了最小值为 `1MiB` 的限制。 |
| TiKV | [`raftstore.store-io-pool-size`](/tikv-configuration-file.md#store-io-pool-size-从-v530-版本开始引入) | 修改 | 为了提升 TiKV 性能，该参数默认值从 `0` 修改为 `1`，表示 StoreWriter 线程池的大小默认为 `1`。|
| TiKV | [`rocksdb.defaultcf.titan.blob-cache-size`](/tikv-configuration-file.md#blob-cache-size) | 修改 | 从 v8.0.0 开始，TiKV 引入了 `shared-blob-cache` 配置项并默认开启，因此无需再单独设置 `blob-cache-size`。只有当 `shared-blob-cache` 设置为 `false` 时，`blob-cache-size` 的设置才生效。|
| TiKV | [`security.encryption.master-key.vendor`](/encryption-at-rest.md#通过-kms-指定主密钥) | 修改 | 主密钥可选的服务商类型新增 `gcp`。 |
-| TiKV | [`rocksdb.defaultcf.titan.shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache-tidb-从-v800-版本开始引入) | 新增 | 控制是否启用 Titan Blob 文件和 RocksDB Block 文件的共享缓存。默认值为 `true`。|
+| TiKV | [`rocksdb.defaultcf.titan.shared-blob-cache`](/tikv-configuration-file.md#shared-blob-cache从-v800-版本开始引入) | 新增 | 控制是否启用 Titan Blob 文件和 RocksDB Block 文件的共享缓存。默认值为 `true`。|
| TiKV | [`security.encryption.master-key.gcp.credential-file-path`](/encryption-at-rest.md#通过-kms-指定主密钥) | 新增 | 在 `security.encryption.master-key.vendor` 为 `gcp` 时，用于指定 Google Cloud 认证凭证文件的路径。|
| TiDB Lightning | [`tikv-importer.duplicate-resolution`](/tidb-lightning/tidb-lightning-physical-import-mode-usage.md#旧版冲突检测从-v800-开始已被废弃) | 废弃 | 用于在物理导入模式下设置是否检测和解决唯一键冲突的记录。从 v8.0.0 开始使用参数 [`conflict.strategy`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-任务配置) 替代。 |
| TiDB Lightning | [`conflict.precheck-conflict-before-import`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-任务配置) | 新增 | 控制是否开启前置冲突检测，即导入数据到 TiDB 前，先检查所需导入的数据是否存在冲突。该参数默认值为 `false`，表示仅开启后置冲突检测。仅当导入模式为物理导入模式 (`tikv-importer.backend = "local"`) 时可以使用该参数。 |
-| TiDB Lightning | [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) | 新增 | 用于在逻辑导入模式下设置一个 batch 里提交的数据行数，默认值为 `65536`。 |
-| TiDB Lightning | [`logical-import-batch-size`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) | 新增 | 用于在逻辑导入模式下设置一个 batch 里提交的数据大小，取值为字符串类型，默认值为 `"96KiB"`，单位可以为 KB、KiB、MB、MiB 等存储单位。 |
+| TiDB Lightning | [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-任务配置) | 新增 | 用于在逻辑导入模式下设置一个 batch 里提交的数据行数，默认值为 `65536`。 |
+| TiDB Lightning | [`logical-import-batch-size`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-任务配置) | 新增 | 用于在逻辑导入模式下设置一个 batch 里提交的数据大小，取值为字符串类型，默认值为 `"96KiB"`，单位可以为 KB、KiB、MB、MiB 等存储单位。 |
| Data Migration | [`secret-key-path`](/dm/dm-master-configuration-file.md) | 新增 | 用于指定加解密上下游密码的密钥文件所在的路径。该文件内容必须是长度为 64 个字符的十六进制的 AES-256 密钥。 |
-| TiCDC | [`tls-certificate-file`](ticdc/ticdc-sink-to-pulsar.md) | 新增 | 用于指定 Pulsar 启用 TLS 加密传输时，客户端的加密证书文件路径。 |
-| TiCDC | [`tls-key-file-path`](ticdc/ticdc-sink-to-pulsar.md) | 新增 | 用于指定 Pulsar 启用 TLS 加密传输时，客户端的加密私钥路径。 |
+| TiCDC | [`tls-certificate-file`](/ticdc/ticdc-sink-to-pulsar.md) | 新增 | 用于指定 Pulsar 启用 TLS 加密传输时，客户端的加密证书文件路径。 |
+| TiCDC | [`tls-key-file-path`](/ticdc/ticdc-sink-to-pulsar.md) | 新增 | 用于指定 Pulsar 启用 TLS 加密传输时，客户端的加密私钥路径。 |
### 系统表
-* 新增系统表 [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md) 和 [`INFORMATION_SCHEMA.CLUSTER_TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md#cluster_tidb_index_usage) 用于记录 TiDB 节点中索引的访问统计信息。**tw@Oreoxmt**
-* 新增系统数据库 [`sys`](/sys-schema.md) 和 [`sys.schema_unused_index`](/sys-schema.md#schema_unused_index) 视图，用于记录自 TiDB 上次启动以来未被使用的索引信息。**tw@Oreoxmt**
+* 新增系统表 [`INFORMATION_SCHEMA.TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md) 和 [`INFORMATION_SCHEMA.CLUSTER_TIDB_INDEX_USAGE`](/information-schema/information-schema-tidb-index-usage.md#cluster_tidb_index_usage) 用于记录 TiDB 节点中索引的访问统计信息。
+* 新增系统数据库 [`sys`](/sys-schema.md) 和 [`sys.schema_unused_index`](/sys-schema.md#schema_unused_index) 视图，用于记录自 TiDB 上次启动以来未被使用的索引信息。
## 废弃功能
-* 从 v8.0.0 开始，[`tidb_disable_txn_auto_retry`](/system-variables.md#tidb_disable_txn_auto_retry) 变量被废弃。废弃后，TiDB 不再支持乐观事务的自动重试。作为替代，当使用乐观事务模式发生冲突时，请在应用里捕获错误并重试，或改用[悲观事务模式](/pessimistic-transaction.md)。**tw@lilin90**
+* 从 v8.0.0 开始，[`tidb_disable_txn_auto_retry`](/system-variables.md#tidb_disable_txn_auto_retry) 变量被废弃。废弃后，TiDB 不再支持乐观事务的自动重试。作为替代，当使用乐观事务模式发生冲突时，请在应用里捕获错误并重试，或改用[悲观事务模式](/pessimistic-transaction.md)。
* 从 v8.0.0 开始，TiDB 不再支持 TLSv1.0 和 TLSv1.1 协议。请升级 TLS 至 TLSv1.2 或 TLSv1.3。
* 计划在后续版本重新设计[执行计划绑定的自动演进](/sql-plan-management.md#自动演进绑定-baseline-evolution)，相关的变量和行为会发生变化。
## 改进提升
-+ TiDB
++ TiDB
- DDL 创建表语句 `CREATE TABLE` 执行性能加速 10 倍，并且可线性扩展 [#50052](https://github.com/pingcap/tidb/issues/50052) @[GMHDBJD](https://github.com/GMHDBJD)
- - 支持同时提交 16 个 `IMPORT INTO ... FROM FILE` 任务，方便批量导入数据到目标表，极大地提升了数据文件导入的效率和性能 [#49008](https://github.com/pingcap/tidb/issues/49008) @[D3Hunter](https://github.com/D3Hunter) **tw@qiancai**
- - 提升 `Sort` 算子的数据落盘性能 [#47733](https://github.com/pingcap/tidb/issues/47733) @[xzhangxian1008](https://github.com/xzhangxian1008) **tw@Oreoxmt**
- - 优化数据落盘功能的退出机制，支持在数据落盘过程中取消查询 [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12) **tw@qiancai**
- - 在处理包含多个等值条件的表连接查询时，支持使用匹配部分条件的索引构造 Index Join [#47233](https://github.com/pingcap/tidb/issues/47233) @[winoros](https://github.com/winoros) **tw@Oreoxmt**
+ - 支持同时提交 16 个 `IMPORT INTO ... FROM FILE` 任务，方便批量导入数据到目标表，极大地提升了数据文件导入的效率和性能 [#49008](https://github.com/pingcap/tidb/issues/49008) @[D3Hunter](https://github.com/D3Hunter)
+ - 提升 `Sort` 算子的数据落盘性能 [#47733](https://github.com/pingcap/tidb/issues/47733) @[xzhangxian1008](https://github.com/xzhangxian1008)
+ - 优化数据落盘功能的退出机制，支持在数据落盘过程中取消查询 [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12)
+ - 在处理包含多个等值条件的表连接查询时，支持使用匹配部分条件的索引构造 Index Join [#47233](https://github.com/pingcap/tidb/issues/47233) @[winoros](https://github.com/winoros)
- 增强 Index Merge 能力，使其能识别查询中的排序需求，并能选中满足排序要求的索引 [#48359](https://github.com/pingcap/tidb/issues/48359) @[AilinKid](https://github.com/AilinKid)
- 当 `Apply` 算子没有并发执行时，支持通过执行 `SHOW WARNINGS` 查看阻碍并发的算子名 [#50256](https://github.com/pingcap/tidb/issues/50256) @[hawkingrei](https://github.com/hawkingrei)
- 优化点查的索引选择，在所有的索引都支持点查时选择其中性能最优的一个用于查询 [#50184](https://github.com/pingcap/tidb/issues/50184) @[elsa0520](https://github.com/elsa0520)
@@ -386,9 +386,13 @@ TiDB 版本：8.0.0
- 在 `PREPARE` 语句无法命中执行计划缓存时，支持通过执行 `SHOW WARNINGS` 查看原因 [#50407](https://github.com/pingcap/tidb/issues/50407) @[hawkingrei](https://github.com/hawkingrei)
- 提升当多次更新同一行的数据时查询估算信息的准确性 [#47523](https://github.com/pingcap/tidb/issues/47523) @[terry1purcell](https://github.com/terry1purcell)
- Index Merge 支持在 `AND` 谓词中内嵌多值索引和 `OR` 操作符 [#51778](https://github.com/pingcap/tidb/issues/51778) @[time-and-fate](https://github.com/time-and-fate)
- - (dup): release-7.1.4.md > 改进提升> TiDB - 当设置 `force-init-stats` 为 `true` 时，即 TiDB 启动时等待统计信息初始化完成后再对外提供服务，这一设置不再影响 HTTP server 提供服务，用户仍可查看监控 [#50854](https://github.com/pingcap/tidb/issues/50854) @[hawkingrei](https://github.com/hawkingrei)
+ - 当设置 `force-init-stats` 为 `true` 时，即 TiDB 启动时等待统计信息初始化完成后再对外提供服务，这一设置不再影响 HTTP server 提供服务，用户仍可查看监控 [#50854](https://github.com/pingcap/tidb/issues/50854) @[hawkingrei](https://github.com/hawkingrei)
+ - 支持 MemoryTracker 追踪 `IndexLookup` 算子的内存使用情况 [#45901](https://github.com/pingcap/tidb/issues/45901) @[solotzg](https://github.com/solotzg)
+ - 支持 MemoryTracker 追踪 `MemTableReaderExec` 算子的内存使用情况 [#51456](https://github.com/pingcap/tidb/issues/51456) @[wshwsh12](https://github.com/wshwsh12)
+ - 支持 cancel 正在落盘的查询 [#50511](https://github.com/pingcap/tidb/issues/50511) @[wshwsh12](https://github.com/wshwsh12)
+ - 支持从 PD 批量加载 Region 的功能，加快在对大表查询时，从 KV Range 到 Regions 的转换过程 [#51326](https://github.com/pingcap/tidb/issues/51326) @[SeaRise](https://github.com/SeaRise)
-+ TiKV
++ TiKV
- 增强 TSO 校验检测，提升配置或操作不当时集群 TSO 的鲁棒性 [#16545](https://github.com/tikv/tikv/issues/16545) @[cfzjywxk](https://github.com/cfzjywxk)
- 优化清理悲观锁的逻辑，提高未提交事务的处理性能 [#16158](https://github.com/tikv/tikv/issues/16158) @[cfzjywxk](https://github.com/cfzjywxk)
@@ -401,7 +405,7 @@ TiDB 版本：8.0.0
- 增加 Region worker 和快照生成 worker 的 CPU 监控 [#16562](https://github.com/tikv/tikv/issues/16562) @[Connor1996](https://github.com/Connor1996)
- 增加 peer 和 store 消息的 slow log [#16600](https://github.com/tikv/tikv/issues/16600) @[Connor1996](https://github.com/Connor1996)
-+ PD
++ PD
- 增强 PD 客户端的服务发现能力，提升其高可用性和负载平衡 [#7576](https://github.com/tikv/pd/issues/7576) @[CabinfeverB](https://github.com/CabinfeverB)
- 增强 PD 客户端的重试机制 [#7673](https://github.com/tikv/pd/issues/7673) @[JmPotato](https://github.com/JmPotato)
@@ -410,68 +414,60 @@ TiDB 版本：8.0.0
- 增加更多心跳监控，以便更好地分析性能瓶颈 [#7868](https://github.com/tikv/pd/issues/7868) @[nolouch](https://github.com/nolouch)
- 减少 etcd leader 对 PD leader 的影响 [#7499](https://github.com/tikv/pd/issues/7499) @[JmPotato](https://github.com/JmPotato) @[HuSharp](https://github.com/HuSharp)
- 增强对不健康的 etcd 节点的检测机制 [#7730](https://github.com/tikv/pd/issues/7730) @[JmPotato](https://github.com/JmPotato) @[HuSharp](https://github.com/HuSharp)
- - 优化 pd-ctl 中 GC safepoint 的相关显示 [#7767](https://github.com/tikv/pd/issues/7767) @[nolouch](https://github.com/nolouch)
- - 支持动态修改热点调度器中的历史窗口配置 [#7877](https://github.com/tikv/pd/issues/7877) @[lhy1024](https://github.com/lhy1024)
- - 减少创建 operator 中的锁争用问题 [#7837](https://github.com/tikv/pd/issues/7837) @[Leavrth](https://github.com/Leavrth)
- - 调整 GRPC 配置以提升可用性 [#7821](https://github.com/tikv/pd/issues/7821) @[rleungx](https://github.com/rleungx)
-
+ - 优化 pd-ctl 中 GC safepoint 的相关显示 [#7767](https://github.com/tikv/pd/issues/7767) @[nolouch](https://github.com/nolouch)
+ - 支持动态修改热点调度器中的历史窗口配置 [#7877](https://github.com/tikv/pd/issues/7877) @[lhy1024](https://github.com/lhy1024)
+ - 减少创建 operator 中的锁争用问题 [#7837](https://github.com/tikv/pd/issues/7837) @[Leavrth](https://github.com/Leavrth)
+ - 调整 GRPC 配置以提升可用性 [#7821](https://github.com/tikv/pd/issues/7821) @[rleungx](https://github.com/rleungx)
+ TiFlash
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - (dup): release-7.6.0.md > 改进提升> TiFlash - 支持在存算分离架构下通过合并相同数据的读取操作，提升多并发下的数据扫描性能 [#6834](https://github.com/pingcap/tiflash/issues/6834) @[JinheLin](https://github.com/JinheLin)
+ - 支持 `JSON_EXTRACT()` 函数中的 `json_path` 参数为非常量 [#8510](https://github.com/pingcap/tiflash/issues/8510) @[SeaRise](https://github.com/SeaRise)
+ - 支持 `JSON_LENGTH(json, path)` 函数输入两个参数 [#8711](https://github.com/pingcap/tiflash/issues/8711) @[SeaRise](https://github.com/SeaRise)
+ Tools
- + Backup & Restore (BR)
+ + Backup & Restore (BR)
- - 支持通过新增的恢复参数 `--load-stats` 控制是否恢复统计信息 [#50568](https://github.com/pingcap/tidb/issues/50568) @[Leavrth](https://github.com/Leavrth)
+ - 支持通过 `br` 命令行工具新增的恢复参数 `--load-stats` 控制是否恢复统计信息 [#50568](https://github.com/pingcap/tidb/issues/50568) @[Leavrth](https://github.com/Leavrth)
+ - 支持通过 `br` 命令行工具新增的恢复参数 `--tikv-max-restore-concurrency` 控制每个 TiKV 节点的最大 download 和 ingest 文件数量，并通过控制作业队列的最大长度，进而控制 BR 节点的内存消耗 [#51621](https://github.com/pingcap/tidb/issues/51621) @[3pointer](https://github.com/3pointer)
- 粗粒度打散 Region 算法支持自适应获取并发参数，提升恢复性能 [#50701](https://github.com/pingcap/tidb/issues/50701) @[3pointer](https://github.com/3pointer)
- 在 `br` 的命令行帮助信息中显示 `log` 命令 [#50927](https://github.com/pingcap/tidb/issues/50927) @[RidRisR](https://github.com/RidRisR)
- 支持在恢复过程中提前分配好 Table ID，从而最大限度地复用 Table ID，提升恢复性能 [#51736](https://github.com/pingcap/tidb/issues/51736) @[Leavrth](https://github.com/Leavrth)
- 使用 BR 时，禁用 TiDB 内部的 GC memory limit tuner 功能，避免 OOM 问题 [#51078](https://github.com/pingcap/tidb/issues/51078) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 改进提升> Tools> Backup & Restore (BR) - 使用更优的算法，提升数据恢复过程中 SST 文件合并的速度 [#50613](https://github.com/pingcap/tidb/issues/50613) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 改进提升> Tools> Backup & Restore (BR) - 支持在数据恢复过程中批量创建数据库 [#50767](https://github.com/pingcap/tidb/issues/50767) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 改进提升> Tools> Backup & Restore (BR) - 在日志备份过程中，增加了在日志和监控指标中打印影响 global checkpoint 推进的最慢的 Region 的信息 [#51046](https://github.com/pingcap/tidb/issues/51046) @[YuJuncen](https://github.com/YuJuncen)
- - (dup): release-7.5.1.md > 改进提升> Tools> Backup & Restore (BR) - 提升了 `RESTORE` 语句在大数据量表场景下的建表性能 [#48301](https://github.com/pingcap/tidb/issues/48301) @[Leavrth](https://github.com/Leavrth)
+ - 使用更优的算法，提升数据恢复过程中 SST 文件合并的速度 [#50613](https://github.com/pingcap/tidb/issues/50613) @[Leavrth](https://github.com/Leavrth)
+ - 支持在数据恢复过程中批量创建数据库 [#50767](https://github.com/pingcap/tidb/issues/50767) @[Leavrth](https://github.com/Leavrth)
+ - 在日志备份过程中，增加了在日志和监控指标中打印影响 global checkpoint 推进的最慢的 Region 的信息 [#51046](https://github.com/pingcap/tidb/issues/51046) @[YuJuncen](https://github.com/YuJuncen)
+ - 提升了 `RESTORE` 语句在大数据量表场景下的建表性能 [#48301](https://github.com/pingcap/tidb/issues/48301) @[Leavrth](https://github.com/Leavrth)
- + TiCDC
+ + TiCDC
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- 优化 `RowChangedEvent` 的内存占用，降低 TiCDC 同步数据时的内存消耗 [#10386](https://github.com/pingcap/tiflow/issues/10386) @[lidezhu](https://github.com/lidezhu)
- 增加在创建和恢复 changefeed 任务时验证 `start-ts` 参数是否合法 [#10499](https://github.com/pingcap/tiflow/issues/10499) @[3AceShowHand](https://github.com/3AceShowHand)
- + TiDB Data Migration (DM)
+ + TiDB Data Migration (DM)
- - 在 MariaDB 主从复制的场景中，即 MariaDB 主实例 -> MariaDB 从实例 -> DM -> TiDB 的迁移场景，当 `gtid_strict_mode = off` 且 MariaDB 从实例的 GTID 不严格递增时（例如，有业务数据写入 MariaDB 从实例），此时 DM 任务会报错 `less than global checkpoint position`。从 v8.0.0 开始，TiDB 兼容该场景，数据可以正常迁移到下游。[#10741](https://github.com/pingcap/tiflow/issues/10741) @[okJiang](https://github.com/okJiang) **tw@hfxsd**
+ - 在 MariaDB 主从复制的场景中，即 MariaDB 主实例 -> MariaDB 从实例 -> DM -> TiDB 的迁移场景，当 `gtid_strict_mode = off` 且 MariaDB 从实例的 GTID 不严格递增时（例如，有业务数据写入 MariaDB 从实例），此时 DM 任务会报错 `less than global checkpoint position`。从 v8.0.0 开始，TiDB 兼容该场景，数据可以正常迁移到下游。[#10741](https://github.com/pingcap/tiflow/issues/10741) @[okJiang](https://github.com/okJiang)
- + TiDB Lightning
+ + TiDB Lightning
- - 在逻辑导入模式下，支持使用 [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-task) 配置批处理的最大行数 [#46607](https://github.com/pingcap/tidb/issues/46607) @[kennytm](https://github.com/kennytm)
+ - 在逻辑导入模式下，支持使用 [`logical-import-batch-rows`](/tidb-lightning/tidb-lightning-configuration.md#tidb-lightning-任务配置) 配置批处理的最大行数 [#46607](https://github.com/pingcap/tidb/issues/46607) @[kennytm](https://github.com/kennytm)
- 当 TiFlash 的导入空间不足时，TiDB Lightning 会报错 [#50324](https://github.com/pingcap/tidb/issues/50324) @[okJiang](https://github.com/okJiang)
- + TiUP
-
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
-
## 错误修复
-+ TiDB
++ TiDB
- 修复在无数据变更的情况下，`auto analyze` 被多次触发的问题 [#51775](https://github.com/pingcap/tidb/issues/51775) @[hi-rustin](https://github.com/hi-rustin)
- 修复 `auto analyze` 并发设置错误的问题 [#51749](https://github.com/pingcap/tidb/issues/51749) @[hawkingrei](https://github.com/hawkingrei)
- 修复使用单个 SQL 语句添加多个索引导致的索引不一致问题 [#51746](https://github.com/pingcap/tidb/issues/51746) @[tangenta](https://github.com/tangenta)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复查询使用 `NATURAL JOIN` 时可能报错 `Column ... in from clause is ambiguous` 的问题 [#32044](https://github.com/pingcap/tidb/issues/32044) @[AilinKid](https://github.com/AilinKid)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复 TiDB 错误地消除 `group by` 中的常量值导致查询结果出错的问题 [#38756](https://github.com/pingcap/tidb/issues/38756) @[hi-rustin](https://github.com/hi-rustin)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复 `LEADING` hint 在 `UNION ALL` 语句中无法生效的问题 [#50067](https://github.com/pingcap/tidb/issues/50067) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复 `BIT` 类型的列在参与一些函数计算时，可能会因为 decode 失败导致查询出错的问题 [#49566](https://github.com/pingcap/tidb/issues/49566) [#50850](https://github.com/pingcap/tidb/issues/50850) [#50855](https://github.com/pingcap/tidb/issues/50855) @[jiyfhust](https://github.com/jiyfhust)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复通过 `tiup cluster upgrade/start` 方式进行滚动升级时，与 PD 交互出现问题可能导致 TiDB panic 的问题 [#50152](https://github.com/pingcap/tidb/issues/50152) @[zimulala](https://github.com/zimulala)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复执行包含 `ORDER BY` 的 `UNIQUE` 索引点查时可能报错的问题 [#49920](https://github.com/pingcap/tidb/issues/49920) @[jackysp](https://github.com/jackysp)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复常量传播在处理 `ENUM` 或 `SET` 类型时结果出错的问题 [#49440](https://github.com/pingcap/tidb/issues/49440) @[winoros](https://github.com/winoros)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复包含 Apply 操作的查询在报错 `fatal error: concurrent map writes` 后导致 TiDB 崩溃的问题 [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复使用 `SET_VAR` 控制字符串类型的变量可能会失效的问题 [#50507](https://github.com/pingcap/tidb/issues/50507) @[qw4990](https://github.com/qw4990)
+ - 修复查询使用 `NATURAL JOIN` 时可能报错 `Column ... in from clause is ambiguous` 的问题 [#32044](https://github.com/pingcap/tidb/issues/32044) @[AilinKid](https://github.com/AilinKid)
+ - 修复 TiDB 错误地消除 `group by` 中的常量值导致查询结果出错的问题 [#38756](https://github.com/pingcap/tidb/issues/38756) @[hi-rustin](https://github.com/hi-rustin)
+ - 修复 `LEADING` hint 在 `UNION ALL` 语句中无法生效的问题 [#50067](https://github.com/pingcap/tidb/issues/50067) @[hawkingrei](https://github.com/hawkingrei)
+ - 修复 `BIT` 类型的列在参与一些函数计算时，可能会因为 decode 失败导致查询出错的问题 [#49566](https://github.com/pingcap/tidb/issues/49566) [#50850](https://github.com/pingcap/tidb/issues/50850) [#50855](https://github.com/pingcap/tidb/issues/50855) @[jiyfhust](https://github.com/jiyfhust)
+ - 修复通过 `tiup cluster upgrade/start` 方式进行滚动升级时，与 PD 交互出现问题可能导致 TiDB panic 的问题 [#50152](https://github.com/pingcap/tidb/issues/50152) @[zimulala](https://github.com/zimulala)
+ - 修复执行包含 `ORDER BY` 的 `UNIQUE` 索引点查时可能报错的问题 [#49920](https://github.com/pingcap/tidb/issues/49920) @[jackysp](https://github.com/jackysp)
+ - 修复常量传播在处理 `ENUM` 或 `SET` 类型时结果出错的问题 [#49440](https://github.com/pingcap/tidb/issues/49440) @[winoros](https://github.com/winoros)
+ - 修复包含 Apply 操作的查询在报错 `fatal error: concurrent map writes` 后导致 TiDB 崩溃的问题 [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
+ - 修复使用 `SET_VAR` 控制字符串类型的变量可能会失效的问题 [#50507](https://github.com/pingcap/tidb/issues/50507) @[qw4990](https://github.com/qw4990)
- 修复当 `tidb_sysdate_is_now` 设置为 `1` 时，`SYSDATE()` 函数错误地使用了计划缓存中的时间的问题 [#49299](https://github.com/pingcap/tidb/issues/49299) @[hawkingrei](https://github.com/hawkingrei)
- 修复执行 `CREATE GLOBAL BINDING` 语句时，如果数据库名为大写，则绑定不生效的问题 [#50646](https://github.com/pingcap/tidb/issues/50646) @[qw4990](https://github.com/qw4990)
- 修复 `Index Path` 选中重复索引的问题 [#50496](https://github.com/pingcap/tidb/issues/50496) @[AilinKid](https://github.com/AilinKid)
@@ -488,72 +484,82 @@ TiDB 版本：8.0.0
- 修复 `init-stats` 流程可能导致 TiDB panic 以及 `load stats` 流程直接退出的问题 [#51581](https://github.com/pingcap/tidb/issues/51581) @[hawkingrei](https://github.com/hawkingrei)
- 修复 `IN()` 谓词中包含 `NULL` 时，查询结果错误的问题 [#51560](https://github.com/pingcap/tidb/issues/51560) @[winoros](https://github.com/winoros)
- 修复当 DDL 任务中包含多张表时，MDL View 中不显示 blocked DDL 的问题 [#47743](https://github.com/pingcap/tidb/issues/47743) @[wjhuang2016](https://github.com/wjhuang2016)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复表的 `ANALYZE` 任务统计的 `processed_rows` 可能超过表的总行数的问题 [#50632](https://github.com/pingcap/tidb/issues/50632) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复当 `HashJoin` 算子落盘失败时 goroutine 可能泄露的问题 [#50841](https://github.com/pingcap/tidb/issues/50841) @[wshwsh12](https://github.com/wshwsh12)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复 CTE 查询使用的内存超限时可能会导致 goroutine 泄露的问题 [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
- - (dup): release-7.5.1.md > 错误修复> TiDB - 修复使用聚合函数分组计算时可能报错 `Can't find column ...` 的问题 [#50926](https://github.com/pingcap/tidb/issues/50926) @[qw4990](https://github.com/qw4990)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复当 `CREATE TABLE` 语句中包含特定分区或约束的表达式时，表名变更等 DDL 操作会卡住的问题 [#50972](https://github.com/pingcap/tidb/issues/50972) @[lcwangchao](https://github.com/lcwangchao)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复 Grafana 监控指标 `tidb_statistics_auto_analyze_total` 没有显示为整数的问题 [#51051](https://github.com/pingcap/tidb/issues/51051) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复修改变量 `tidb_server_memory_limit` 后，`tidb_gogc_tuner_threshold` 未进行相应调整的问题 [#48180](https://github.com/pingcap/tidb/issues/48180) @[hawkingrei](https://github.com/hawkingrei)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复当查询语句涉及 JOIN 操作时可能出现 `index out of range` 报错的问题 [#42588](https://github.com/pingcap/tidb/issues/42588) @[AilinKid](https://github.com/AilinKid)
- - (dup): release-7.1.4.md > 错误修复> TiDB - 修复当列的默认值被删除时，获取该列的默认值会报错的问题 [#50043](https://github.com/pingcap/tidb/issues/50043) [#51324](https://github.com/pingcap/tidb/issues/51324) @[crazycs520](https://github.com/crazycs520)
+ - 修复表的 `ANALYZE` 任务统计的 `processed_rows` 可能超过表的总行数的问题 [#50632](https://github.com/pingcap/tidb/issues/50632) @[hawkingrei](https://github.com/hawkingrei)
+ - 修复当 `HashJoin` 算子落盘失败时 goroutine 可能泄露的问题 [#50841](https://github.com/pingcap/tidb/issues/50841) @[wshwsh12](https://github.com/wshwsh12)
+ - 修复 CTE 查询使用的内存超限时可能会导致 goroutine 泄露的问题 [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
+ - 修复使用聚合函数分组计算时可能报错 `Can't find column ...` 的问题 [#50926](https://github.com/pingcap/tidb/issues/50926) @[qw4990](https://github.com/qw4990)
+ - 修复当 `CREATE TABLE` 语句中包含特定分区或约束的表达式时，表名变更等 DDL 操作会卡住的问题 [#50972](https://github.com/pingcap/tidb/issues/50972) @[lcwangchao](https://github.com/lcwangchao)
+ - 修复 Grafana 监控指标 `tidb_statistics_auto_analyze_total` 没有显示为整数的问题 [#51051](https://github.com/pingcap/tidb/issues/51051) @[hawkingrei](https://github.com/hawkingrei)
+ - 修复修改变量 `tidb_server_memory_limit` 后，`tidb_gogc_tuner_threshold` 未进行相应调整的问题 [#48180](https://github.com/pingcap/tidb/issues/48180) @[hawkingrei](https://github.com/hawkingrei)
+ - 修复当查询语句涉及 JOIN 操作时可能出现 `index out of range` 报错的问题 [#42588](https://github.com/pingcap/tidb/issues/42588) @[AilinKid](https://github.com/AilinKid)
+ - 修复当列的默认值被删除时，获取该列的默认值会报错的问题 [#50043](https://github.com/pingcap/tidb/issues/50043) [#51324](https://github.com/pingcap/tidb/issues/51324) @[crazycs520](https://github.com/crazycs520)
- 修复 TiFlash 延迟物化在处理关联列时结果可能出错的问题 [#49241](https://github.com/pingcap/tidb/issues/49241) [#51204](https://github.com/pingcap/tidb/issues/51204) @[Lloyd-Pottiger](https://github.com/Lloyd-Pottiger)
-
-+ TiKV
-
- - (dup): release-7.5.1.md > 错误修复> TiKV - 修复开启 `tidb_enable_row_level_checksum` 可能导致 TiKV panic 的问题 [#16371](https://github.com/tikv/tikv/issues/16371) @[cfzjywxk](https://github.com/cfzjywxk)
- - (dup): release-7.1.4.md > 错误修复> TiKV - 修复休眠的 Region 在异常情况下未被及时唤醒的问题 [#16368](https://github.com/tikv/tikv/issues/16368) @[LykxSassinator](https://github.com/LykxSassinator)
- - (dup): release-7.1.4.md > 错误修复> TiKV - 通过在执行下线节点操作前检查该 Region 所有副本的上一次心跳时间，修复下线一个副本导致整个 Region 不可用的问题 [#16465](https://github.com/tikv/tikv/issues/16465) @[tonyxuqqi](https://github.com/tonyxuqqi)
- - (dup): release-7.1.4.md > 错误修复> TiKV - 修复 JSON 整型数值在大于 `INT64` 最大值但小于 `UINT64` 最大值时会被 TiKV 解析成 `FLOAT64` 导致结果和 TiDB 不一致的问题 [#16512](https://github.com/tikv/tikv/issues/16512) @[YangKeao](https://github.com/YangKeao)
- - 修复监控指标 `tikv_unified_read_pool_thread_count` 有时没有数据的问题 [#16629](https://github.com/tikv/tikv/issues/16629) @[YuJuncen](https://github.com/YuJuncen)
-
-+ PD
-
- - (dup): release-7.1.4.md > 错误修复> PD - 修复调用 `MergeLabels` 函数时存在数据竞争的问题 [#7535](https://github.com/tikv/pd/issues/7535) @[lhy1024](https://github.com/lhy1024)
- - (dup): release-7.1.4.md > 错误修复> PD - 修复调用 `evict-leader-scheduler` 接口时没有输出结果的问题 [#7672](https://github.com/tikv/pd/issues/7672) @[CabinfeverB](https://github.com/CabinfeverB)
- - (dup): release-7.5.1.md > 错误修复> PD - 修复 PD 监控项 `learner-peer-count` 在发生 Leader 切换后未同步旧监控值的问题 [#7728](https://github.com/tikv/pd/issues/7728) @[CabinfeverB](https://github.com/CabinfeverB)
- - (dup): release-7.1.4.md > 错误修复> PD - 修复 `watch etcd` 没有正确关闭导致内存泄露的问题 [#7807](https://github.com/tikv/pd/issues/7807) @[rleungx](https://github.com/rleungx)
- - (dup): release-7.1.4.md > 修复 TSO 部分日志没有打印报错原因的问题 [#7496](https://github.com/tikv/pd/issues/7496) @[CabinfeverB](https://github.com/CabinfeverB)
+ - 修复 `LIKE()` 函数在处理 binary collation 的输入时可能结果错误的问题 [#50393](https://github.com/pingcap/tidb/issues/50393) @[yibin87](https://github.com/yibin87)
+ - 修复在并行 Apply 时可能会因为并发写导致 TiDB crash 的问题 [#50347](https://github.com/pingcap/tidb/issues/50347) @[SeaRise](https://github.com/SeaRise)
+ - 修复 `JSON_LENGTH()` 函数在第二个参数为 `NULL` 时结果错误的问题 [#50931](https://github.com/pingcap/tidb/issues/50931) @[SeaRise](https://github.com/SeaRise)
+ - 修复包含 `CTE` 的查询在内存超限后可能导致 Goroutine 泄露的问题 [#50337](https://github.com/pingcap/tidb/issues/50337) @[guo-shaoge](https://github.com/guo-shaoge)
+ - 修复 `CAST(AS DATETIME)` 在特定情况下可能会丢失时间精度的问题 [#49555](https://github.com/pingcap/tidb/issues/49555) @[SeaRise](https://github.com/SeaRise)
+ - 修复并行 Apply 在表为聚簇索引时可能导致结果错误的问题 [#51372](https://github.com/pingcap/tidb/issues/51372) @[guo-shaoge](https://github.com/guo-shaoge)
+ - 修复主键类型是 `VARCHAR` 时，执行 `ALTER TABLE ... COMPACT TIFLASH REPLICA` 可能会错误地提前结束的问题 [#51810](https://github.com/pingcap/tidb/issues/51810) @[breezewish](https://github.com/breezewish)
+
++ TiKV
+
+ - 修复开启 `tidb_enable_row_level_checksum` 可能导致 TiKV panic 的问题 [#16371](https://github.com/tikv/tikv/issues/16371) @[cfzjywxk](https://github.com/cfzjywxk)
+ - 修复休眠的 Region 在异常情况下未被及时唤醒的问题 [#16368](https://github.com/tikv/tikv/issues/16368) @[LykxSassinator](https://github.com/LykxSassinator)
+ - 通过在执行下线节点操作前检查该 Region 所有副本的上一次心跳时间，修复下线一个副本导致整个 Region 不可用的问题 [#16465](https://github.com/tikv/tikv/issues/16465) @[tonyxuqqi](https://github.com/tonyxuqqi)
+ - 修复 JSON 整型数值在大于 `INT64` 最大值但小于 `UINT64` 最大值时会被 TiKV 解析成 `FLOAT64` 导致结果和 TiDB 不一致的问题 [#16512](https://github.com/tikv/tikv/issues/16512) @[YangKeao](https://github.com/YangKeao)
+ - 修复监控指标 `tikv_unified_read_pool_thread_count` 有时没有数据的问题 [#16629](https://github.com/tikv/tikv/issues/16629) @[YuJuncen](https://github.com/YuJuncen)
+
++ PD
+
+ - 修复调用 `MergeLabels` 函数时存在数据竞争的问题 [#7535](https://github.com/tikv/pd/issues/7535) @[lhy1024](https://github.com/lhy1024)
+ - 修复调用 `evict-leader-scheduler` 接口时没有输出结果的问题 [#7672](https://github.com/tikv/pd/issues/7672) @[CabinfeverB](https://github.com/CabinfeverB)
+ - 修复 PD 监控项 `learner-peer-count` 在发生 Leader 切换后未同步旧监控值的问题 [#7728](https://github.com/tikv/pd/issues/7728) @[CabinfeverB](https://github.com/CabinfeverB)
+ - 修复 `watch etcd` 没有正确关闭导致内存泄露的问题 [#7807](https://github.com/tikv/pd/issues/7807) @[rleungx](https://github.com/rleungx)
+ - 修复 TSO 部分日志没有打印报错原因的问题 [#7496](https://github.com/tikv/pd/issues/7496) @[CabinfeverB](https://github.com/CabinfeverB)
- 修复重启后 PD 部分监控出现非预期负数的问题 [#4489](https://github.com/tikv/pd/issues/4489) @[lhy1024](https://github.com/lhy1024)
- 修复 Leader 租约的过期时间晚于日志时间的问题 [#7700](https://github.com/tikv/pd/issues/7700) @[CabinfeverB](https://github.com/CabinfeverB)
- - 修复 PD 客户端 TLS 相关的问题 [#7900](https://github.com/tikv/pd/issues/7900) [#7902](https://github.com/tikv/pd/issues/7902) [#7916](https://github.com/tikv/pd/issues/7916) @[CabinfeverB](https://github.com/CabinfeverB)
+ - 修复在 TiDB（PD 客户端）和 PD 之间的 TLS 开关不一致时，TiDB panic 的问题 [#7900](https://github.com/tikv/pd/issues/7900) [#7902](https://github.com/tikv/pd/issues/7902) [#7916](https://github.com/tikv/pd/issues/7916) @[CabinfeverB](https://github.com/CabinfeverB)
- 修复 Goroutine 由于没有正确关闭而泄露的问题 [#7782](https://github.com/tikv/pd/issues/7782) @[HuSharp](https://github.com/HuSharp)
- 修复 pd-ctl 无法移除包含特殊字符的调度器的问题 [#7798](https://github.com/tikv/pd/issues/7798) @[JmPotato](https://github.com/JmPotato)
- 修复 PD 客户端获取 TSO 可能被阻塞的问题 [#7864](https://github.com/tikv/pd/issues/7864) @[CabinfeverB](https://github.com/CabinfeverB)
-+ TiFlash
++ TiFlash
- - (dup): release-7.5.1.md > 错误修复> TiFlash - 修复副本迁移时，因 TiFlash 与 PD 之间网络连接不稳定可能引发的 TiFlash panic 的问题 [#8323](https://github.com/pingcap/tiflash/issues/8323) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > 错误修复> TiFlash - 修复慢查询导致内存使用显著增加的问题 [#8564](https://github.com/pingcap/tiflash/issues/8564) @[JinheLin](https://github.com/JinheLin)
- - (dup): release-7.5.1.md > 错误修复> TiFlash - 修复移除 TiFlash 副本后重新添加可能导致 TiFlash 数据损坏的问题 [#8695](https://github.com/pingcap/tiflash/issues/8695) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > 错误修复> TiFlash - 修复在执行 PITR 恢复任务或 `FLASHBACK CLUSTER TO` 后，TiFlash 副本数据可能被意外删除，导致数据异常的问题 [#8777](https://github.com/pingcap/tiflash/issues/8777) @[JaySon-Huang](https://github.com/JaySon-Huang)
- - (dup): release-7.5.1.md > 错误修复> TiFlash - 修复在执行 `ALTER TABLE ... MODIFY COLUMN ... NOT NULL` 时，将原本可为空的列修改为不可为空之后，导致 TiFlash panic 的问题 [#8419](https://github.com/pingcap/tiflash/issues/8419) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - 修复副本迁移时，因 TiFlash 与 PD 之间网络连接不稳定可能引发的 TiFlash panic 的问题 [#8323](https://github.com/pingcap/tiflash/issues/8323) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - 修复慢查询导致内存使用显著增加的问题 [#8564](https://github.com/pingcap/tiflash/issues/8564) @[JinheLin](https://github.com/JinheLin)
+ - 修复移除 TiFlash 副本后重新添加可能导致 TiFlash 数据损坏的问题 [#8695](https://github.com/pingcap/tiflash/issues/8695) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - 修复在执行 PITR 恢复任务或 `FLASHBACK CLUSTER TO` 后，TiFlash 副本数据可能被意外删除，导致数据异常的问题 [#8777](https://github.com/pingcap/tiflash/issues/8777) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - 修复在执行 `ALTER TABLE ... MODIFY COLUMN ... NOT NULL` 时，将原本可为空的列修改为不可为空之后，导致 TiFlash panic 的问题 [#8419](https://github.com/pingcap/tiflash/issues/8419) @[JaySon-Huang](https://github.com/JaySon-Huang)
- 修复存算分离架构下，出现网络隔离后查询可能会被永久阻塞的问题 [#8806](https://github.com/pingcap/tiflash/issues/8806) @[JinheLin](https://github.com/JinheLin)
- 修复存算分离架构下，TiFlash 关闭过程中可能 panic 的问题 [#8837](https://github.com/pingcap/tiflash/issues/8837) @[JaySon-Huang](https://github.com/JaySon-Huang)
+ - 修复 TiFlash 在发生远程读时可能会因为数据竞争导致 crash 的问题 [#8685](https://github.com/pingcap/tiflash/issues/8685) @[solotzg](https://github.com/solotzg)
+ - 修复 `CAST(AS JSON)` 函数中没有对 JSON object key 去重的问题 [#8712](https://github.com/pingcap/tiflash/issues/8712) @[SeaRise](https://github.com/SeaRise)
+ - 修复 `ENUM` 列在 chunk encode 时可能会导致 TiFlash crash 的问题 [#8674](https://github.com/pingcap/tiflash/issues/8674) @[yibin87](https://github.com/yibin87)
+ Tools
- + Backup & Restore (BR)
+ + Backup & Restore (BR)
- 修复在 Region 成为 Leader 后立刻分裂或合并，导致日志备份 Checkpoint 不推进的问题 [#16469](https://github.com/tikv/tikv/issues/16469) @[YuJuncen](https://github.com/YuJuncen)
- 修复在某些极端情况下，全量备份因找不到 peer 导致 TiKV panic 的问题 [#16394](https://github.com/tikv/tikv/issues/16394) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复在同一节点上更改 TiKV IP 地址导致日志备份卡住的问题 [#50445](https://github.com/pingcap/tidb/issues/50445) @[3pointer](https://github.com/3pointer)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复从 S3 读文件内容时出错后无法重试的问题 [#49942](https://github.com/pingcap/tidb/issues/49942) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复数据恢复失败后，使用断点重启报错 `the target cluster is not fresh` 的问题 [#50232](https://github.com/pingcap/tidb/issues/50232) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复停止日志备份任务导致 TiDB crash 的问题 [#50839](https://github.com/pingcap/tidb/issues/50839) @[YuJuncen](https://github.com/YuJuncen)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复由于某个 TiKV 节点缺少 Leader 导致数据恢复变慢的问题 [#50566](https://github.com/pingcap/tidb/issues/50566) @[Leavrth](https://github.com/Leavrth)
- - (dup): release-7.5.1.md > 错误修复> Tools> Backup & Restore (BR) - 修复全量恢复指定 `--filter` 选项后，仍然要求目标集群为空的问题 [#51009](https://github.com/pingcap/tidb/issues/51009) @[3pointer](https://github.com/3pointer)
-
- + TiCDC
-
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复使用 storage sink 时，在存储服务生成的文件序号可能出现回退的问题 [#10352](https://github.com/pingcap/tiflow/issues/10352) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复并发创建多个 changefeed 时 TiCDC 返回 `ErrChangeFeedAlreadyExists` 错误的问题 [#10430](https://github.com/pingcap/tiflow/issues/10430) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复在 `ignore-event` 中设置了过滤掉 `add table partition` 事件后，TiCDC 未将相关分区的其它类型 DML 变更事件同步到下游的问题 [#10524](https://github.com/pingcap/tiflow/issues/10524) @[CharlesCheung96](https://github.com/CharlesCheung96)
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复上游表执行了 `TRUNCATE PARTITION` 后 changefeed 报错的问题 [#10522](https://github.com/pingcap/tiflow/issues/10522) @[sdojjy](https://github.com/sdojjy)
- - (dup): release-7.1.4.md > 错误修复> Tools> TiCDC - 修复恢复 changefeed 时 changefeed 的 `checkpoint-ts` 小于 TiDB 的 GC safepoint，没有及时报错 `snapshot lost caused by GC` 的问题 [#10463](https://github.com/pingcap/tiflow/issues/10463) @[sdojjy](https://github.com/sdojjy)
- - (dup): release-7.1.4.md > 错误修复> Tools> TiCDC - 修复 TiCDC 在开启单行数据正确性校验后由于时区不匹配导致 `TIMESTAMP` 类型 checksum 验证失败的问题 [#10573](https://github.com/pingcap/tiflow/issues/10573) @[3AceShowHand](https://github.com/3AceShowHand)
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复 Syncpoint 表可能被错误同步的问题 [#10576](https://github.com/pingcap/tiflow/issues/10576) @[asddongmen](https://github.com/asddongmen)
- - (dup): release-7.5.1.md > 错误修复> Tools> TiCDC - 修复当使用 Apache Pulsar 作为下游时，无法正常启用 OAuth2.0、TLS 和 mTLS 的问题 [#10602](https://github.com/pingcap/tiflow/issues/10602) @[asddongmen](https://github.com/asddongmen)
+ - 修复在同一节点上更改 TiKV IP 地址导致日志备份卡住的问题 [#50445](https://github.com/pingcap/tidb/issues/50445) @[3pointer](https://github.com/3pointer)
+ - 修复从 S3 读文件内容时出错后无法重试的问题 [#49942](https://github.com/pingcap/tidb/issues/49942) @[Leavrth](https://github.com/Leavrth)
+ - 修复数据恢复失败后，使用断点重启报错 `the target cluster is not fresh` 的问题 [#50232](https://github.com/pingcap/tidb/issues/50232) @[Leavrth](https://github.com/Leavrth)
+ - 修复停止日志备份任务导致 TiDB crash 的问题 [#50839](https://github.com/pingcap/tidb/issues/50839) @[YuJuncen](https://github.com/YuJuncen)
+ - 修复由于某个 TiKV 节点缺少 Leader 导致数据恢复变慢的问题 [#50566](https://github.com/pingcap/tidb/issues/50566) @[Leavrth](https://github.com/Leavrth)
+ - 修复全量恢复指定 `--filter` 选项后，仍然要求目标集群为空的问题 [#51009](https://github.com/pingcap/tidb/issues/51009) @[3pointer](https://github.com/3pointer)
+
+ + TiCDC
+
+ - 修复使用 storage sink 时，在存储服务生成的文件序号可能出现回退的问题 [#10352](https://github.com/pingcap/tiflow/issues/10352) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - 修复并发创建多个 changefeed 时 TiCDC 返回 `ErrChangeFeedAlreadyExists` 错误的问题 [#10430](https://github.com/pingcap/tiflow/issues/10430) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - 修复在 `ignore-event` 中设置了过滤掉 `add table partition` 事件后，TiCDC 未将相关分区的其它类型 DML 变更事件同步到下游的问题 [#10524](https://github.com/pingcap/tiflow/issues/10524) @[CharlesCheung96](https://github.com/CharlesCheung96)
+ - 修复上游表执行了 `TRUNCATE PARTITION` 后 changefeed 报错的问题 [#10522](https://github.com/pingcap/tiflow/issues/10522) @[sdojjy](https://github.com/sdojjy)
+ - 修复恢复 changefeed 时 changefeed 的 `checkpoint-ts` 小于 TiDB 的 GC safepoint，没有及时报错 `snapshot lost caused by GC` 的问题 [#10463](https://github.com/pingcap/tiflow/issues/10463) @[sdojjy](https://github.com/sdojjy)
+ - 修复 TiCDC 在开启单行数据正确性校验后由于时区不匹配导致 `TIMESTAMP` 类型 checksum 验证失败的问题 [#10573](https://github.com/pingcap/tiflow/issues/10573) @[3AceShowHand](https://github.com/3AceShowHand)
+ - 修复 Syncpoint 表可能被错误同步的问题 [#10576](https://github.com/pingcap/tiflow/issues/10576) @[asddongmen](https://github.com/asddongmen)
+ - 修复当使用 Apache Pulsar 作为下游时，无法正常启用 OAuth2.0、TLS 和 mTLS 的问题 [#10602](https://github.com/pingcap/tiflow/issues/10602) @[asddongmen](https://github.com/asddongmen)
- 修复当 TiKV 升级、重启或驱逐 Leader 时，changefeed 可能卡住的问题 [#10584](https://github.com/pingcap/tiflow/issues/10584) @[asddongmen](https://github.com/asddongmen)
- 修复在频繁执行 DDL 的场景中，由于错误的 BarrierTS 导致数据被写入到错误的 CSV 文件的问题 [#10668](https://github.com/pingcap/tiflow/issues/10668) @[lidezhu](https://github.com/lidezhu)
- 修复 KV Client 数据争用导致 TiCDC panic 的问题 [#10718](https://github.com/pingcap/tiflow/issues/10718) @[asddongmen](https://github.com/asddongmen)
@@ -566,23 +572,8 @@ TiDB 版本：8.0.0
+ TiDB Lightning
- 修复检查 TiKV 空间导致的性能回退的问题 [#43636](https://github.com/pingcap/tidb/issues/43636) @[lance6716](https://github.com/lance6716)
- - (dup): release-7.1.4.md > 错误修复> Tools> TiDB Lightning - 修复在扫描数据文件时，遇到不合法符号链接文件而报错的问题 [#49423](https://github.com/pingcap/tidb/issues/49423) @[lance6716](https://github.com/lance6716)
- - (dup): release-7.1.4.md > 错误修复> Tools> TiDB Lightning - 修复当 `sql_mode` 中不包含 `NO_ZERO_IN_DATE` 时，TiDB Lightning 无法正确解析包含 `0` 的日期值的问题 [#50757](https://github.com/pingcap/tidb/issues/50757) @[GMHDBJD](https://github.com/GMHDBJD)
-
- + Dumpling
-
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
-
- + TiUP
-
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
-
- + TiDB Binlog
-
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
- - note [#issue](链接) @[贡献者 GitHub ID](链接)
+ - 修复在扫描数据文件时，遇到不合法符号链接文件而报错的问题 [#49423](https://github.com/pingcap/tidb/issues/49423) @[lance6716](https://github.com/lance6716)
+ - 修复当 `sql_mode` 中不包含 `NO_ZERO_IN_DATE` 时，TiDB Lightning 无法正确解析包含 `0` 的日期值的问题 [#50757](https://github.com/pingcap/tidb/issues/50757) @[GMHDBJD](https://github.com/GMHDBJD)
## 贡献者
|