v1.21-1-17

1. Exception prompt for adding single table failed
2. Fix the MHA cluster heartbeat statement error
3. Explain statement supports displaying collocatedpushdown
4. Fix the inconsistency between the fields of the back-end pull result set and the MYCAT CREATE TABLE statement. There is no exception prompt, but the empty result set is displayed
5. Fix the error that the sortjoin optimization rule does not solve the parameterized expression
6. Support select @ @ foreign_ KEY_ CHECKS,SELECT @@innodb_ file_ per_ table =1; The return values are fixed and used for compatibility with some frameworks
7. Reconstruct the preprocessing, support sysbanch test, be compatible with the preprocessing statements of MySQL C client, and improve the deprecateeof compatibility
8. Improve the partition tailoring and push down of < = > semantics
9. The default JDBC querytimeout is 0
10. Heartbeat configuration supports the showlog attribute to configure heartbeat log output
11. Partitionbyprefixpattern / partitionbypattern / partitionbymurmurhash / partitionbyfilemap / autopartitionbylong support mapfile attribute
12. Ignore the error of XA recoverylog when initializing the database, because XA is not used for read-write separation
13. Partitionbypattern supports the defaultnode attribute
14. The condition of update / delete statement supports table Expression for column
15. Fix the problem that JDBC manager cannot load mongodb driver
16. Fix the problem of not writing the alias 1054 unknown column in 'where clause' under a single node
17. You can use SQL to create fragment tables without configuring C0 nodes
18. Fix the null result set error of show global variables
19. Failed to repair delete table configuration
20. Utf8 code is used for repairing and building database, and now it has been changed to utf8mb4 code
21. The repair meta information table has no built-in parameters
22. Fix the error that DDL cannot be executed in parallel (#631)
23. Support lock function
24. Support virtual tables
25. Support MYCAT UI