pingcap/tidb v4.0.2

tidb-server v4.0.2

on GitHub

Compatibility Changes

• Remove sensitive information in the slow query log and the statement summary table #18130
• Forbid negative value in the sequence cache #18103
• Remove tombstone TiKV and TiFlash stores from the CLUSTER_INFO table #17953
• Change the diagnostic rule from current-load to node-check #17660

New Features

• Support the MEMORY_QUOTA() hint in INSERT statements #18101
• Support authentication based on the SAN field of TLS certificate #17698
• Support collation for the REGEXP() function #17581
• Support the sql_select_limit session and global variable #17604
• Support splitting the Region for the newly added partition by default #17665
• Support pushing the IF()/BITXOR()/BITNEG()/JSON_LENGTH() functions to the TiFlash Coprocessor #17651 #17592
• Support a new aggregate function APPROX_COUNT_DISTINCT() to calculate the approximate result of COUNT(DISTINCT) #18120
• Support collation in TiFlash and pushing collation-related functions to TiFlash #17705
• Add the STATUS_ADDRESS column in the INFORMATION_SCHEMA.INSPECTION_RESULT table to indicate the status address of servers #17695
• Add the SOURCE column in the MYSQL.BIND_INFO table to indicate the how the bindings are created #17587
• Add the PLAN_IN_CACHE and PLAN_CACHE_HITS columns in the PERFORMANCE_SCHEMA.EVENTS_STATEMENTS_SUMMARY_BY_DIGEST table to indicate the plan cache usage of SQL statements #17493
• Add the enable-collect-execution-info configuration item and the tidb_enable_collect_execution_info session variable to control whether to collect execution information of each operator and record the information in the slow query log #18073 #18072
• Add the tidb_slow_log_masking global variable to control whether to desensitize the queries in slow query log #17694
• Add a diagnostic rule in the INFORMATION_SCHEMA.INSPECTION_RESULT table for the storage.block-cache.capacity TiKV configuration item #17671
• Add the BACKUP and RESTORE SQL statements to back up and restore data #15274

Improvements

• Reduce the query latency caused by the Golang memory allocation when CM-Sketch consumes too much memory #17545
• Reduce the QPS recovery duration of a cluster when a TiKV server is in the failure recovery process #17681
• Support pushing aggregate functions to TiKV/TiFlash Coprocessor on partition tables #17655
• Improve the accuracy of row count estimation for index equal conditions #17611

Bug Fixes

• Fix the issue of incorrect execution plan obtained from the plan cache after tidb_isolation_read_engines is changed #17570
• Fix the occasional runtime error that occurs when executing the EXPLAIN FOR CONNECTION statement #18124
• Fix the incorrect result of the last_plan_from_cache session variable in some cases #18111
• Fix the runtime error that occurs when executing the UNIX_TIMESTAMP() function from the plan cache #18002 #17673
• Fix the runtime error when the child of HashJoin executor returns the NULL column #17937
• Fix the runtime error caused by concurrently executing the DROP DATABASE statement and other DDL statements in the same database #17659
• Fix the incorrect result of the COERCIBILITY() function on user variables #17890
• Fix the issue that the IndexMergeJoin executor occasionally gets stuck #18091
• Fix the hang issue of the IndexMergeJoin executor when out of memory quota and query cancelling is triggered #17654
• Fix the excessive counting memory usage of the Insert and Replace executors #18062
• Fix the issue that the data replication to TiFlash storage is stopped when DROP DATABASE and DROP TABLE are executed concurrently in the same database #17901
• Fix the BACKUP/RESTORE failure between TiDB and the object storage service #17844
• Fix the incorrect error message of privilege check failure when access is denied #17724
• Discard the query feedbacks generated from the DELETE/UPDATE statement #17843
• Forbid altering AUTO_RANDOM_BASE for a table without AUTO_RANDOM property #17828
• Fix the issue that some system tables cannot be accessed when setting the value of tidb_isolation_read_engines without tidb #17719
• Fix the inaccurate result of JSON comparison on large integers and float values #17717
• Fix the incorrect decimal property for the result of the COUNT() function #17704
• Fix the incorrect result of the HEX() function when the type of input is the binary string #17620
• Fix the issue that an empty result is returned when querying the INFORMATION_SCHEMA.INSPECTION_SUMMARY table without filter condition #17697
• Fix the issue that the hashed password used by the ALTER USER statement to update user information is unexpected #17646
• Support collation for ENUM and SET values #17701
• Fix the issue that the timeout mechanism for pre-splitting Regions does not work when creating a table #17619
• Fix the issue that the schema is unexpectedly updated when a DDL job is retried, which might break the atomicity of DDL jobs #17608
• Fix the incorrect result of the FIELD() function when the argument contains the column #17562
• Fix the issue that the max_execution_time hint does not work occasionally #17536
• Fix the issue that the concurrency information is redundantly printed in the result of EXPLAIN ANALYZE #17350
• Fix the incompatible behavior of %h on the STR_TO_DATE function #17498
• Fix the issue that the follower/learner keeps retrying when tidb_replica_read is set to follower and there is a network partition between the leader and the follower/learner #17443
• Fix the issue that TiDB sends too many pings to PD follower in some cases #17947
• Fix the issue that the range partition table of older versions cannot be loaded in TiDB v4.0 #17983
• Fix the SQL statement timeout issue when multiple Region requests fail at the same time by assigning different Backoffer for each Region #17585
• Fix the MySQL incompatible behavior when parsing DateTime delimiters #17501
• Fix the issue that TiKV requests are occasionally sent to the TiFlash server #18105