TiDB 3.0.14 Release Notes

Release date: May 9, 2020

TiDB version: 3.0.14

Compatibility Changes

• TiDB

  • Adjust the user privilege in performance_schema and metrics_schema from read-write to read-only #15417

Important Bug Fixes

• TiDB

  • Fix the issue that the query result of index join is incorrect when the join condition has multiple equivalent conditions on the column with the handle attribute #15734
  • Fix the panic that occurs when performing the fast analyze operation on the column with the handle attribute #16079
  • Fix the issue that the query field in the DDL job structure is incorrect when the DDL statement is executed in a way of prepare. This issue might cause data inconsistency between the upstream and the downstream when Binlog is used for data replication. #15443

• TiKV

  • Fix the issue that repeated requests on the cleanup of lock might destroy the atomicity of the transaction #7388

New Features

• TiDB

  • Add the schema name column and the table name column to the query results of the admin show ddl jobs statement #16428
  • Enhance the RECOVER TABLE syntax to support recovering truncated tables #15458
  • Support the privilege check for the SHOW GRANTS statement #16168
  • Support the privilege check for the LOAD DATA statement #16736
  • Improve the performance of partition pruning when functions related to time and date are used as partition keys #15618
  • Adjust the log level of dispatch error from WARN to ERROR #16232
  • Support the require-secure-transport startup option to force clients to use TLS #15415
  • Support HTTP communication between TiDB components when TLS is configured #15419
  • Add the start_ts information of the current transaction to the information_schema.processlist table #16160
  • Support automatically reloading the TLS certificate information used for communication among clusters #15162
  • Improve the read performance of the partitioned tables by restructuring the partition pruning #15628
  • Support the partition pruning feature when floor(unix_timestamp(a)) is used as the partition expression of the range partition table #16521
  • Allow executing the update statement that contains a view and does not update the view #16787
  • Prohibit creating nested views #15424
  • Prohibit truncating view #16420
  • Prohibit using the update statement to explicitly update the values of a column when this column is not in the public state #15576
  • Prohibit starting TiDB when the status port is occupied #15466
  • Change the character set of the current_role function from binary to utf8mb4 #16083
  • Improve max-execution-time usability by checking the interrupt signal when the data of a new Region is read #15615
  • Add the ALTER TABLE ... AUTO_ID_CACHE syntax for explicitly setting the cache step of auto_id #16287

• TiKV

  • Improve the performance when many conflicts and the BatchRollback condition exist in optimistic transactions #7605
  • Fix the issue of decreased performance that occurs because the pessimistic lock waiter is frequently awakened when many conflicts exist in pessimistic transactions #7584

• Tools

  • TiDB Lightning

    • Support printing the TiKV cluster mode using the fetch-mode sub-command of tidb-lightning-ctl #287

Bug Fixes

• TiDB

  • Fix the issue that WEEKEND function is not compatible with MySQL when the SQL mode is ALLOW_INVALID_DATES #16170
  • Fix the issue that the DROP INDEX statement fails to execute when the index column contains the auto-increment primary key #16008
  • Fix the issue of incorrect values of the TABLE_NAMES column in the Statement Summary #15231
  • Fix the issue that some expressions have incorrect results when the plan cache is enabled #16184
  • Fix the issue that the result of the not/istrue/isfalse function is incorrect #15916
  • Fix the panic caused by the MergeJoin operation on tables with redundant indexes #15919
  • Fix the issue caused by incorrectly simplifying the link when the predicate only refers to the outer table #16492
  • Fix the issue that the CURRENT_ROLE function reports an error caused by the SET ROLE statement #15569
  • Fix the issue that the result of the LOAD DATA statement is incompatible with MySQL when this statement encounters \ #16633
  • Fix the issue that the database visibility is incompatible with MySQL #14939
  • Fix the issue of incorrect privilege check for the SET DEFAULT ROLE ALL statement #15585
  • Fix the issue of partition pruning failure caused by the plan cache #15818
  • Fix the issue that schema change is reported during the transaction commit when concurrent DDL operations are performed on a table and blocking exists, because the transaction does not lock the related table #15707
  • Fix the incorrect behavior of IF(not_int, *, *) #15356
  • Fix the incorrect behavior of CASE WHEN (not_int) #15359
  • Fix the issue that the Unknown column error message is returned when using a view that is not in the current schema #15866
  • Fix the issue that the result of parsing time strings is incompatible with MySQL #16242
  • Fix the possible panic of the collation operator in left join when a null column exists in the right child node #16528
  • Fix the issue that no error message is returned even though the SQL execution is blocked when TiKV keeps returning the StaleCommand error message #16528
  • Fix the possible panic caused by the port probing when the audit plugin is enabled #15967
  • Fix the panic caused when fast analyze works on indices only #15967
  • Fix the possible panic of the SELECT * FROM INFORMATION_SCHEMA.PROCESSLIST statement execution in some cases #16309
  • Fix the issue of TiDB OOM caused by specifying a large number of partitions (for example, 9999999999999) when the hash partition table is created without checking the number of partitions before allocating memory #16218
  • Fix the issue of incorrect information of partitioned tables in information_schema.tidb_hot_table #16726
  • Fix the issue that the partition selection algorithm does not take effect on the hash partitioned table #16070
  • Fix the issue that the HTTP API of the MVCC series does not support partitioned tables #16191
  • Keep the error handling of the UNION statement consistent with that of the SELECT statement #16137
  • Fix the issue of incorrect behavior when the parameter type of the VALUES function is bit(n) #15486
  • Fix the issue that the processing logic of TiDB is inconsistent with MySQL when the view column name is too long. In this case, the system automatically generates a short column name. #14873
  • Fix the issue that (not not col) is incorrectly optimized as col #16094
  • Fix the issue of incorrect range of the inner table built by IndexLookupJoin plans #15753
  • Fix the issue that only_full_group_by fails to correctly check expressions with brackets #16012
  • Fix the issue that an error is returned when the select view_name.col_name from view_name statement is executed #15572

• TiKV

  • Fix the issue that the node cannot be deleted correctly after the isolation recovery in some cases #7703
  • Fix the issue of data loss during network isolation caused by the Region Merge operation #7679
  • Fix the issue that learner cannot be removed correctly in some cases #7598
  • Fix the issue that the scanning result of raw key-value pairs might be out of order #7597
  • Fix the issue of reconnection when the batch of Raft messages is too large #7542
  • Fix the issue of gRPC thread deadlock caused by the empty request #7538
  • Fix the issue that the processing logic of restarting the learner is incorrect during the merge process #7457
  • Fix the issue that repeated requests on the cleanup of lock might destroy the atomicity of the transaction #7388