feature (hereinafter referred to as "database auditing") is released in TiDB v7.1.0, replacing the legacy audit plugin (hereinafter referred to as "audit plugin"). This article describes how to use Database plugin to database auditing The legacy TiDB audit plugin has no conflict with the new database auditing. Starting from TiDB v7.1, it is recommended to migrate the legacy plugin to the new database auditing After the configuration is completed and verified, execute the following command to disable the legacy audit plugin: mysql> admin plugins disable audit; © 2023 PingCAP. All Rights Reserved. 20

memory and actual storage size is too large ● Reader doesn’t require stong consistency ● Migrate from legacy MySQL applications Aurora typical scenarios What’s TiDB TiKV Node N Store N TiKV Node 1 Store

Controls whether TiDB uses an opti- mized version of the Hash Join opera- tor. The default value of legacy means that the opti- mized version is not used. If you set it to optimized �→ , TiDB uses the opti- Ketanji Brown Jackson. One of our nation’s top legal minds, who will �→ continue Justice Breyer’s legacy of excellence. -------------------------------------------------------------------------------- Ketanji Brown Jackson. One of our nation’s top legal minds, who will �→ continue Justice Breyer’s legacy of excellence. --------------------------------------------------------------------------------

Controls whether TiDB uses an opti- mized version of the Hash Join opera- tor. The default value of legacy means that the opti- mized version is not used. If you set it to optimized �→ , TiDB uses the opti- Ketanji Brown Jackson. One of our nation’s top legal minds, who will �→ continue Justice Breyer’s legacy of excellence. -------------------------------------------------------------------------------- Ketanji Brown Jackson. One of our nation’s top legal minds, who will �→ continue Justice Breyer’s legacy of excellence. --------------------------------------------------------------------------------

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · 473 4.11.3 Legacy Docs · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · - List of Expressions for Pushdown. • Predicate push down. 4.11.3 Legacy Docs 4.11.3.1 App Development for Django Note: This legacy document is outdated and will not be updated thereafter. You can see an experimental feature. It is not recom- mended that you use it in the production environment. • LEGACY (default): The GC leader sends requests to all Regions to scan obsolete locks, checks the primary

entries. TiKV automatically compacts data in background while TiDB Lightning is importing. Note: For legacy reasons, you can still configure TiDB Lightning to explicitly trig- ger a compaction every time a you use it in the production environment. • Scope: GLOBAL • Default value: LEGACY • Possible values: PHYSICAL, LEGACY – LEGACY: Uses the old way of scanning, that is, disable Green GC. – PHYSICAL: Uses specifies the way of scanning locks in the Resolve Locks step of GC. When the variable value is set to LEGACY, TiDB scans locks by Regions. When the value PHYSICAL is used, it enables each TiKV node to bypass

entries. TiKV automatically compacts data in background while TiDB Lightning is importing. Note: For legacy reasons, you can still configure TiDB Lightning to explicitly trig- ger a compaction every time a use it in production environments. 1401 • Scope: GLOBAL • Default value: LEGACY • Possible values: PHYSICAL, LEGACY – LEGACY: Uses the old way of scanning, that is, disable Green GC. – PHYSICAL: Uses specifies the way of scanning locks in the Resolve Locks step of GC. When the variable value is set to LEGACY, TiDB scans locks by Regions. When the value PHYSICAL is used, it enables each TiKV node to bypass

entries. TiKV automatically compacts data in background while TiDB Lightning is importing. Note: For legacy reasons, you can still configure TiDB Lightning to explicitly trig- ger a compaction every time a you use it in the production environment. • Scope: GLOBAL • Default value: LEGACY • Possible values: PHYSICAL, LEGACY – LEGACY: Uses the old way of scanning, that is, disable Green GC. – PHYSICAL: Uses specifies the way of scanning locks in the Resolve Locks step of GC. When the variable value is set to LEGACY, TiDB scans locks by Regions. When the value PHYSICAL is used, it enables each TiKV node to bypass

entries. TiKV automatically compacts data in background while TiDB Lightning is importing. Note: For legacy reasons, you can still configure TiDB Lightning to explicitly trig- ger a compaction every time a that you use it in production environments. • Scope: GLOBAL • Default value: LEGACY • Possible values: PHYSICAL, LEGACY – LEGACY: Uses the old way of scanning, that is, disable Green GC. – PHYSICAL: Uses specifies the way of scanning locks in the Resolve Locks step of GC. When the variable value is set to LEGACY, TiDB scans locks by Regions. When the value PHYSICAL is used, it enables each TiKV node to bypass

行统计 信息自 动更新 任务。 tidb_hash �→ _join_ �→ version �→ 新增 控制 TiDB 是 否使用 Hash Join 算子的 优化版。 默认值 为 legacy， 表示不 使用优 化版。 如果设 置为 optimized �→ ， TiDB 在 执行 Hash Join 算子时 将使用 其优化 版，以 提升 Hash Join 性能。 47 Ketanji Brown Jackson. �→ One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of �→ excellence. -------------------------------------------------------------------------------- Ketanji Brown Jackson. �→ One of our nation’s top legal minds, who will continue Justice Breyer’s legacy of �→ excellence. --------------------------------------------------------------------------------