TiDB - v5.4.0

Improvements

• Add a new system variable tidb_enable_paging to determine whether to use paging to send Coprocessor requests. Enabling this feature can reduce the amount of data to process and to reduce latency and resource consumption #30578
• Support the ADMIN {SESSION | INSTANCE | GLOBAL} PLAN_CACHE syntax to clear the cached query plan #30370

Bug fixes

• Fix the issue of the tidb_analyze_version value change that occurs when upgrading the cluster from v4.x to v5.x #25422
• Fix the issue of the wrong result that occurs when using different collations in a subquery #30748
• Fix the issue that the result of concat(ifnull(time(3)) in TiDB is different from that in MySQL #29498
• Fix the issue of potential data index inconsistency in optimistic transaction mode #30410
• Fix the issue that the query execution plan of IndexMerge is wrong when an expression cannot be pushed down to TiKV #30200
• Fix the issue that concurrent column type change causes inconsistency between the schema and the data #31048
• Fix the issue that the IndexMerge query result is wrong when there is a subquery #30913
• Fix the panic issue that occurs when the FetchSize is set too large in the client #30896
• Fix the issue that LEFT JOIN might be mistakenly converted to INNER JOIN #20510
• Fix the issue that panic might occur when the CASE-WHEN expression and collation are used together #30245
• Fix the issue of wrong query result that occurs when the IN value contains a binary constant #31261
• Fix the issue of wrong query result that occurs when CTE has a subquery #31255
• Fix the issue that executing the INSERT ... SELECT ... ON DUPLICATE KEY UPDATE statement gets panic #28078
• Fix the issue that INDEX HASH JOIN returns the send on closed channel error #31129