Weekly update in TiDB

Last week, we landed 30 PRs in the TiDB repositories, 3 PRs in the TiDB docs repositories.

Added

• Add a session variable to skip unique constraint check: This could be used when migrating data.

• More metrics for statement counter.

Fixed

• Use reserved keywords as the table/column name.

• Add missing comments in the show table status result.

• Fix a bug that gets duplicate auto_inc ID after truncating table..

Improved

• Make the Explain result more explicit.

• Tune the package size to be friendly for rocksdb.

• Use a better way to reload schema and reduce memory usage.

• Fetch schemas in a parallel way to make it faster when there are a huge number of schemas and tables.

Document change

Add the following new guides:

• Compatibility with MySQL.

• Reading data from history versions.

Weekly update in TiKV

Last week, we landed 19 PRs in the TiKV repositories.

Fixed

• Check whether the message is discarded after proposing.

Improved

• Still refactor cache to make it more easily to use, with PR 360, 382.

• Add lock Time To Live (TTL) for large transactions.

• Try updating the soft limit when requirement check fails.

• Support configuring fill cache.

• Limit the WriteBatch size for the ResolveLock and Garbage Collection commands.

• Clean up unnecessary filter args.

• Abstract a Selector to handle different strategies to select stores.

• Enlarge the latches size of the scheduler to reduce lock conflicts.