tidb v4.0.3 Release Notes

Release Date: 2020-07-24 // over 3 years ago
  • ๐Ÿ‘Œ Improvements

    • ๐ŸŒฒ Add the tidb_log_desensitization global variable to control whether to do desensitization when logging SQL queries #18581
    • ๐Ÿ‘ Enable tidb_allow_batch_cop by default #18552
    • Speed up canceling a query #18505
    • Add a header for the tidb_decode_plan result #18501
    • ๐Ÿ”ง Make the configuration checker compatible with earlier versions of the configuration file #18046
    • 0๏ธโƒฃ Enable collecting the execution information by default #18518
    • Add the tiflash_tables and tiflash_segments system tables #18536
    • ๐Ÿšš Move AUTO RANDOM out of experimental features and announce its general availability. The improvements and compatibility changes are as follows:
    • ๐Ÿ”ง Deprecate experimental.allow-auto-random in the configuration file. No matter how this item is configured, you can always define the AUTO RANDOM feature on columns. #18613 #18623
    • ๐Ÿ‘ Add the tidb_allow_auto_random_explicit_insert session variable to control the explicit writes on AUTO RANDOM columns. The default value is false. This is to avoid the unexpected AUTO_RANDOM_BASE update caused by explicit writes on columns. #18508
    • ๐Ÿ‘ Allow defining AUTO_RANDOM only on BIGINT and UNSIGNED BIGINT columns and restrict the maximum number of shard bits to 15, which avoids the allocatable space being consumed too quickly #18538
    • Do not trigger the AUTO_RANDOM_BASE update when defining the AUTO_RANDOM attribute on the BIGINT column and inserting the negative value into the primary key #17987
    • ๐Ÿ‘‰ Use the highest bit of an integer for ID allocation when defining the AUTO_RANDOM attribute on UNSIGNED BIGINT columns, which gets more allocable space #18404
    • ๐Ÿ‘Œ Support updating the AUTO_RANDOM attribute in the result of SHOW CREATE TABLE #18316

    ๐Ÿ› Bug Fixes

    • Return an error instead of an empty set for IndexHashJoin when an error occurs during execution #18586
    • ๐Ÿ›  Fix the recurring panic when gRPC transportReader is broken #18562
    • ๐Ÿ›  Fix the issue that Green GC does not scan locks on offline stores which might cause data incompleteness #18550
    • Forbid processing a non-read-only statement using TiFlash engine #18534
    • Return the actual error message when a query connection panics #18500
    • ๐Ÿ›  Fix the issue that the ADMIN REPAIR TABLE execution fails to reload the table metadata on the TiDB node #18323
    • ๐Ÿ›  Fix the data inconsistency issue occurred because the lock of a written and deleted primary key in one transaction is resolved by another transaction #18291
    • ๐Ÿ‘‰ Make spilling disk work well #18288
    • ๐Ÿ›  Fix the error reported when the REPLACE INTO statement works on the table that contains generated columns #17907
    • ๐Ÿ‘ท Return the OOM error when the IndexHashJoin and IndexMergeJoin workers panic #18527
    • ๐Ÿ›  Fix the bug that the execution of Index Join might return wrong results in special cases when the index used by Index Join contains the integer primary key #18565
    • ๐Ÿ›  Fix the issue that when the new collation is enabled on the cluster, the data updated on columns with the new collation in a transaction cannot be read through the unique index #18703