Weekly update in TiDB

Last week, we landed 30 PRs in the TiDB repositories.

Added

• Add context in exector: prepare for canceling execution.

• Support the KILL statement.

• Support string literal with in the national character set N'literal'.

• Check privilege when running create user statement.

• Add a session variable to prevent eager aggregation.

Fixed

• Clean up pending task when close executor: fix memory leak.

• Make the type of coalesce function the same with MySQL.

• Clean up process info when finish running statement.

• Fix a bug in optimizer about pushing down limit across filter.

• Fix a bug in optimizer about column prunning on union statement.

• Use QUOTE as an identifier.

Improved

• Create user automatically when grant privilege for unexist user.

• Speed up Add Column statement.

• Update grpc version to v1.0.4 in vendor.

• Avoid useless schema version update when running DDL.

• Add metrics for potential time-consuming queries.

Weekly update in TiKV

Last week, We landed 13 PRs in the TiKV repositories.

Added

• Add metric for RocksDB compaction.

• Collect scanned key count to detect region access hotspot.

• Support GetRegionByID for pd-ctl.

• Enable AutoCompactionRetention to reduce PD space occupation.

Fixed

• Reduce manual compaction for Lock CF to avoid too many WAL logs.

• Only check scheduler busy error for Write command.

• Fix data race for updating replication configuration.

• Prohibit joining the PD cluster with empty name.

Improved

• Beautify region log.

• Cleanup iterator creation.

• Adjust default leader scheduler limit to speed up leader balance.