Performance Cross-database SQL binding When managing hundreds of databases with the same this case, it is impractical to bind SQL for each database one by �→ one. TiDB v7.6.0 introduces cross-database SQL bindings that enable �→ matching bindings across all schema-equivalent databases. impact on application traffic. For more information, see documentation. 2.2.1.3 Reliability • Cross-database execution plan binding #48875 @qw4990 When running SaaS services on TiDB, it is common practice

of data. Cross-database SQL binding (introduced in v7 �→ .6.0) When managing hundreds this case, it is impractical to bind SQL for each database one by �→ one. TiDB v7.6.0 introduces cross-database SQL bindings that enable �→ matching bindings across all schema-equivalent databases. Y Y Y Y Y Y Y E E Non-prepared statement cache Y Y E N N N N N N SQL binding Y Y Y Y Y Y Y Y Y Cross-database binding Y N N N N N N N N Create bindings according to historical execution plans Y Y Y

of data. Cross-database SQL binding (introduced in v7 �→ .6.0) When managing hundreds this case, it is impractical to bind SQL for each database one by �→ one. TiDB v7.6.0 introduces cross-database SQL bindings that enable �→ matching bindings across all schema-equivalent databases. Y Y Y Y Y Y Y E E Non-prepared statement cache Y Y E N N N N N N SQL binding Y Y Y Y Y Y Y Y Y Cross-database binding Y N N N N N N N N Create bindings according to historical execution plans Y Y Y

Y Y Y Y Y Y Y Y Y Y Y 93 Advanced SQL features 8.4 8.3 8.2 8.1 7.5 7.1 6.5 6.1 5.4 5.3 5.2 5.1 Cross-database binding Y Y Y Y N N N N N N N N Create bindings according to historical execution plans Y Y N N N N N PITR Y Y Y Y Y Y Y N N N N N Global mem- ory con- trol Y Y Y Y Y Y Y N N N N N Cross- cluster RawKV repli- ca- tion E E E E E E E N N N N N 104 Management, ob- serv- abil- ity, and supported starting from TiDB v6.6.0, and generally available starting from v8.5.0. Foreign keys allow cross-table references of related data, while foreign key constraints ensure the consistency of related

Y Y Y Y Y E E Non-prepared statement cache Y Y Y E N N N N N N SQL binding Y Y Y Y Y Y Y Y Y Y Cross-database binding Y Y N N N N N N N N Create bindings according to historical execution plans Y Y 5 6.1 5.4 5.3 5.2 5.1 PITR Y Y Y Y Y N N N N N Global mem- ory con- trol Y Y Y Y Y N N N N N Cross- cluster RawKV repli- ca- tion E E E E E N N N N N Green GC E E E E E E E E E E Resource con- mode: • Foreign key is an experimental feature supported starting from TiDB v6.6.0, which allows cross-table referencing of related data, and foreign key constraints to maintain data consistency. Warning:

Y Y Y E E Non-prepared statement cache Y Y Y Y E N N N N N N SQL binding Y Y Y Y Y Y Y Y Y Y Y Cross-database binding Y Y Y N N N N N N N N Create bindings according to historical execution plans Y Y Y Y Y N N N N N PITR Y Y Y Y Y Y N N N N N Global mem- ory con- trol Y Y Y Y Y Y N N N N N Cross- cluster RawKV repli- ca- tion E E E E E E N N N N N Green GC E E E E E E E E E E E Resource con- mode: • Foreign key is an experimental feature supported starting from TiDB v6.6.0, which allows cross-table referencing of related data, and foreign key constraints to maintain data consistency. Warning:

Y Y Y Y Y Y Y Y Y Y Y 88 Advanced SQL features 8.4 8.3 8.2 8.1 7.5 7.1 6.5 6.1 5.4 5.3 5.2 5.1 Cross-database binding Y Y Y Y N N N N N N N N Create bindings according to historical execution plans Y Y N N N N N PITR Y Y Y Y Y Y Y N N N N N Global mem- ory con- trol Y Y Y Y Y Y Y N N N N N Cross- cluster RawKV repli- ca- tion E E E E E E E N N N N N 99 Management, ob- serv- abil- ity, and mode: • Foreign key is an experimental feature supported starting from TiDB v6.6.0, which allows cross-table referencing of related data, and foreign key constraints to maintain data consistency. Warning:

E E E Non-prepared statement cache Y Y Y E N N N N N N N N SQL binding Y Y Y Y Y Y Y Y Y Y Y Y Cross-database binding Y Y N N N N N N N N N N Create bindings according to historical execution plans N N N N N N N PITR Y Y Y Y Y N N N N N N N Global mem- ory con- trol Y Y Y Y Y N N N N N N N Cross- cluster RawKV repli- ca- tion E E E E E N N N N N N N 99 Management, ob- serv- abil- ity, and 237 • Foreign key is an experimental feature supported starting from TiDB v6.6.0, which allows cross-table referencing of related data, and foreign key constraints to maintain data consistency. Warning:

equipment where cross-CPU access to remote memory will greatly reduce performance. By default, TiDB will use all CPUs of the server, and goroutine scheduling will inevitably lead to cross-CPU memory access score �→ The pa- rame- ter of load �→ - �→ base �→ - �→ split �→ . The smaller the value, the fewer cross- Region visits after Re- gion split. cdc. �→ min �→ - �→ ts �→ - �→ interval �→ The time inter- val Configuration item Description schedule �→ . �→ enable �→ - �→ cross �→ - �→ table �→ - �→ merge �→ Determines whether to en- able cross- table merge schedule �→ . �→ enable �→ - �→ one �→ - �→ way �→

equipment where cross-CPU access to remote memory will greatly reduce performance. By default, TiDB will use all CPUs of the server, and goroutine scheduling will inevitably lead to cross-CPU memory access score �→ The pa- rame- ter of load �→ - �→ base �→ - �→ split �→ . The smaller the value, the fewer cross- Region visits after Re- gion split. In the table above, parameters with the {db-name} or {db-name} en- able isola- tion level check schedule �→ . �→ enable �→ - �→ cross �→ - �→ table �→ - �→ merge �→ Determines whether to en- able cross- table merge schedule �→ . �→ enable �→ - �→ one �→ - �→ way �→