Weekly update in TiDB

Last week, we landed 37 PRs in the TiDB repository.

Added

• Support the SQL_BIG_RESULT, SQL_SMALL_RESULT, and SQL_BUFFER_RESULT syntax
• Add usability-team in PR guidelines

Improved

• Check Deadlock in KeyError of the pessimistic locking operation result returned by TiKV
• Remove canceled requests before sending them to TiKV
• Implement IterReverse and use it to speed up admin show ddl jobs
• Preload frequently used variables
• Improve the UT coverage of the expression package to 80%
• Improve the UT coverage of the distsql package to 85%
• Speed up testing by 50% in the ddl package

Fixed

• Skip virtual generated column during collecting statistics
• Fix a potential goroutine leak in gcworker
• Fix the Analyze worker panic caused by sending messages in the closed channel
• Fix the unexpected result of unsigned_int_col >= -int_cnst in the planner
• Fix a panic when using the Window function in some cases
• Fix SHOW VIEW privileges for EXPLAIN
• Fix the goroutine leak when TiKV is offline
• Fix the issue that StreamAggExec does not clean up resources when the Close function is called

Weekly update in TiSpark

Last week, we landed 4 PRs in the TiSpark repository.

Fixed

• Fix the issue that the MatchError exception might occur when unsigned BigInt is used in the group by column

Weekly update in TiKV and PD

Last week, we landed 38 PRs in the TiKV and PD repositories.

Added

• Add batch aggregate functions
  • SUM()
  • AVG()
  • FIRST()
• Add BatchStreamAggregationExecutor
• Support resolve_lock_lite

Improved

• Reuse monotonic-raw-now for each round in raftstore
• Improve batch vector performance

Fixed

• Fix the issue that the TiKV snapshot might not be synchronized
• Fix the TiKV read stale issue after role change
• Fix the issue that the hot Region limit for PD might be 0
• Fix a TiKV panic when no aggregate function exists in the batch executor
• Fix Duration::parse bugs

New contributors (Thanks!)

tikv:

• senden9

parser:

• b41sh
• db-storage

docs-cn:

• emhlbmc