Last week, we landed 25 PRs in the TiDB repositories and 5 PRs in the TiDB docs repositories.

Weekly update in TiDB

Added

• Support the Alter table modify column statement.

• Support the Drop view statement: parsed but ignored.

• Add metrics for the transaction size.

• A tool for testing the SQL performance.

Fixed

• A bug in the show create table statement.

• A few bugs in optimizer: #1962, #1963, #1966, #1975, #1977.

Improved

• Improve the cost-based optimizer.

Document change

• Adjust the README structure to include the document list

• Add the following new guides:

  • Data migration from MySQL to TiDB

  • Overview of the monitoring framework

  • Monitoring a TiDB cluster

  • Compatibility with MySQL

Weekly update in TiKV

Last week, we landed 23 PRs in the TiKV repositories.

Added

• Resolve locks in batches to avoid generating a huge Raft log when a transaction rolls back.

• Add applying snapshot count to enhance the Placement Driver (PD) balance, with PR 1278, 381.

• Check the system configuration before startup.

Fixed

• Add a start flag to check whether a balance starts or not to fix issue 343.

• Fix the data inconsistency bug when applying snapshot and committed logs at same time.

Improved

• Refactor cache to access easily, with PR 359, 379.

• Update RocksDB config to let user configure it more easily.

• Slow down Raft heartbeat and election interval to reduce the system pressure.

• Check the PD list to ensure the address has a valid format.

• Improve tikv-ctl, with PR 1273, 1281, 1295.