TiDB 6.5.8 Release Notes

Release date: February 2, 2024

TiDB version: 6.5.8

Quick access: Quick start | Production deployment

Compatibility changes

• Introduce the TiKV configuration item gc.num-threads to set the number of GC threads when enable-compaction-filter is false #16101 @tonyxuqqi

Improvements

• TiFlash

  • Reduce the impact of background GC tasks on read and write task latency #8650 @JaySon-Huang

• Tools

  • TiCDC

    • Support querying the downstream synchronization status of a changefeed, which helps you determine whether the upstream data changes received by TiCDC have been synchronized to the downstream system completely #10289 @hongyunyan

  • TiDB Lightning

    • Improve the performance of ALTER TABLE when importing a large number of small tables #50105 @D3Hunter

Bug fixes

• TiDB

  • Fix the issue that enforced sorting might become ineffective when a query uses optimizer hints (such as STREAM_AGG()) that enforce sorting and its execution plan contains IndexMerge #49605 @AilinKid
  • Fix the issue that histogram statistics might not be parsed into readable strings when the histogram boundary contains NULL #49823 @AilinKid
  • Fix the issue that hints cannot be used in REPLACE INTO statements #34325 @YangKeao
  • Fix the issue that query results are incorrect due to STREAM_AGG() incorrectly handling CI #49902 @wshwsh12
  • Fix the issue that the query result of a range partitioned table is incorrect in some cases due to wrong partition pruning #50082 @Defined2014
  • Fix the issue that the auto-increment ID allocation reports an error due to concurrent conflicts when using an auto-increment column with AUTO_ID_CACHE=1 #50519 @tiancaiamao
  • Mitigate the issue that TiDB nodes might encounter OOM errors when dealing with a large number of tables or partitions #50077 @zimulala
  • Fix the issue that data is inconsistent under the TiDB Distributed eXecution Framework (DXF) when executing ADD INDEX after the DDL Owner is network isolated #49773 @tangenta
  • Fix the issue that TiDB might panic when a query contains the Apply operator and the fatal error: concurrent map writes error occurs #50347 @SeaRise
  • Fix the issue that the COMMIT or ROLLBACK operation executed through COM_STMT_EXECUTE fails to terminate transactions that have timed out #49151 @zyguan
  • Fix the issue that executing SELECT INTO OUTFILE using the PREPARE method incorrectly returns a success message instead of an error #49166 @qw4990
  • Fix the issue that executing UNIQUE index lookup with an ORDER BY clause might cause an error #49920 @jackysp
  • Fix the issue that the DELETE and UPDATE statements using index lookup might report an error when tidb_multi_statement_mode mode is enabled #50012 @tangenta
  • Fix the issue that TiDB might not simultaneously establish the new statistics metadata when executing a large number of CREATE TABLE statements in a short period of time #36004 @xuyifangreeneyes
  • Fix the issue that the LEADING hint does not take effect in UNION ALL statements #50067 @hawkingrei
  • Fix the issue that using old interfaces might cause inconsistent metadata for tables #49751 @hawkingrei
  • Fix the issue that common hints do not take effect in UNION ALL statements #50068 @hawkingrei
  • Fix the issue that TiDB returns wrong query results when processing ENUM or SET types by constant propagation #49440 @winoros

• TiKV

  • Fix the issue that TiKV might panic when gRPC threads are checking is_shutdown #16236 @pingyu
  • Fix the issue that TiKV converts the time zone incorrectly for Brazil and Egypt #16220 @overvenus
  • Fix the issue that TiDB and TiKV might produce inconsistent results when processing DECIMAL arithmetic multiplication truncation #16268 @solotzg

• PD

  • Fix the issue that querying a Region without a leader using pd-ctl might cause PD to panic #7630 @rleungx

• TiFlash

  • Fix the issue that the lowerUTF8 and upperUTF8 functions do not allow characters in different cases to occupy different bytes #8484 @gengliqi
  • Fix the issue that TiFlash panics after executing ALTER TABLE ... MODIFY COLUMN ... NOT NULL, which changes nullable columns to non-nullable #8419 @JaySon-Huang
  • Fix the issue that after terminating a query, TiFlash crashes due to concurrent data conflicts when a large number of tasks on TiFlash are canceled at the same time #7432 @SeaRise

• Tools

  • Backup & Restore (BR)

    • Fix the issue that the Unsupported collation error is reported when you restore data from backups of an old version #49466 @3pointer
    • Fix the issue that BR cannot retry when encountering an error while reading file content from S3 #49942 @Leavrth
    • Fix the issue that log backup gets stuck after changing the TiKV IP address on the same node #50445 @3pointer

  • 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 @CharlesCheung96
    • Fix the issue that the changefeed reports an error after TRUNCATE PARTITION is executed on the upstream table #10522 @sdojjy
    • Fix the issue that the changefeed resolved ts does not advance in extreme cases #10157 @sdojjy
    • Fix the issue that TiCDC returns the ErrChangeFeedAlreadyExists error when concurrently creating multiple changefeeds #10430 @CharlesCheung96

  • TiDB Lightning

    • Fix the issue that TiDB Lightning might fail to import data when EBS BR is running #49517 @mittalrishabh
    • Fix the issue that data might be lost when TiDB Lightning ingests files in batches #50198 @D3Hunter