tidb v3.0.1 Release Notes

Release Date: 2019-07-16 // over 4 years ago
    • Add the tidb_wait_split_region_finish_backoff session variable to control the backoff time of splitting Regions #11166
    • ๐Ÿ‘Œ Support automatically adjusting the auto-incremental ID allocation step based on the load, and the auto-adjustment scope of the step is 1000~2000000 #11006
    • โž• Add the ADMIN PLUGINS ENABLE/ADMIN PLUGINS DISABLE SQL statement to dynamically enable or disable plugins #11157
    • โž• Add the session connection information in the audit plugin #11013
    • Add optimizer hint MAX_EXECUTION_TIME, which places a limit N (a timeout value in milliseconds) on how long a SELECT statement is permitted to execute before the server terminates it: #11026
    • ๐Ÿ”„ Change the default behavior during the period of splitting Regions to wait for PD to finish scheduling #11166
    • Prohibit Window Functions from being cached in Prepare Plan Cache to avoid incorrect results in some cases #11048
    • Prohibit ALTER statements from modifying the definition of stored generated columns #11068
    • Disallow changing virtual generated columns to stored generated columns #11068
    • Disallow changing the generated column expression with indexes #11068
    • ๐Ÿ‘Œ Support compiling TiDB on the ARM64 architecture #11150
    • ๐Ÿ‘Œ Support modifying the collation of a database or a table, but the character set of the database/table has to be UTF-8 or utf8mb4 #11086
    • ๐Ÿ›  Fix the issue that an error is reported when the SELECT subquery in the UPDATE โ€ฆ SELECT statement fails to resolve the column in the UPDATE expression #11252
    • ๐Ÿ›  Fix the panic issue that happens when a column is queried on multiple times and the returned result is NULL during point queries #11226
    • ๐Ÿ›  Fix the data race issue caused by non-thread safe rand.Rand when using the RAND function #11169
    • ๐Ÿ›  Fix the bug that the memory usage of a SQL statement exceeds the threshold but the execution of this statement is not canceled in some cases when oom-action="cancel" is configured #11004
    • ๐Ÿ›  Fix the issue that when a query ends, SHOW PROCESSLIST shows that the memory usage is not 0 because the memory usage of MemTracker was not correctly cleaned #10970
    • ๐Ÿ›  Fix the bug that the result of comparing integers and non-integers is not correct in some cases #11194
    • ๐Ÿ›  Fix the bug that the query result is not correct when the query on table partitions contains a predicate in explicit transactions #11196
    • ๐Ÿ›  Fix the DDL job panic issue because infoHandle might be NULL #11022
    • ๐Ÿ›  Fix the issue that the query result is not correct because the queried column is not referenced in the subquery and is then wrongly pruned when running a nested aggregation query #11020
    • ๐Ÿ›  Fix the issue that the Sleep function does not respond to the KILL statement in time #11028
    • ๐Ÿ›  Fix the issue that the DB and INFO columns shown by the SHOW PROCESSLIST command are incompatible with MySQL #11003
    • ๐Ÿ›  Fix the system panic issue caused by the FLUSH PRIVILEGES statement when skip-grant-table=true is configured #11027
    • ๐Ÿ›  Fix the issue that the primary key statistics collected by FAST ANALYZE are not correct when the table primary key is an UNSIGNED integer #11099
    • ๐Ÿ›  Fix the issue that the "invalid key" error is reported by the FAST ANALYZE statement in some cases #11098
    • ๐Ÿ›  Fix the issue that the precision shown by the SHOW CREATE TABLE statement is incomplete when CURRENT_TIMESTAMP is used as the default value of the column and the decimal precision is specified #11088
    • ๐Ÿ›  Fix the issue that the function name is not in lowercase when window functions report an error to make it compatible with MySQL #11118
    • ๐Ÿ›  Fix the issue that TiDB fails to connect to TiKV and thus cannot provide service after the background thread of TiKV Client Batch gRPC panics #11101
    • ๐Ÿ›  Fix the issue that the variable is set incorrectly by SetVar because of the shallow copy of the string #11044
    • ๐Ÿ›  Fix the issue that the execution fails and an error is reported when the INSERT โ€ฆ ON DUPLICATE statement is applied on table partitions #11231
    • Pessimistic locking (experimental feature)
      • Fix the issue that an incorrect result is returned because of the invalid lock on the row when point queries are run using the pessimistic locking and the returned data is empty #10976
      • Fix the issue that the query result is not correct because SELECT โ€ฆ FOR UPDATE does not use the correct TSO when using the pessimistic locking in the query #11015
    • ๐Ÿ”’ Change the detection behavior from immediate conflict detection to waiting when an optimistic transaction meets a pessimistic lock to avoid worsening the lock conflict #11051