2017-07-04-tidb-weekly.md

title	date	summary	tags
Weekly update (June 26 ~ July 02, 2017)	2017-07-04	Last week, we landed 33 PRs in the TiDB repositories and 12 PRs in the TiKV repositories.	TiDB TiKV

Weekly update in TiDB

Last week, we landed 33 PRs in the TiDB repositories.

Added

• Support priority options in the select statement.
• Add the GetOwnerID interface in OwnerManager.
• Add some columns in mysql.db: Make it compatible with MySQL.
• Add the IsolationLevel option in the coprocessor request to TiKV.
• Add the priority option in Key-Value request to TiKV.
• Support the RenameTable statement without the To keyword.

Fixed

• Fix a bug in the update statement like update T set a = 8, b = a.
• Consider the timezone information when using current_timestamp as the default value.
• Break the campaigning owner loop when closing a DDL worker.
• Check the validity of table name in the CreateTable statement.
• Handle the null argument in substr function.
• Disable concurrent pre-write when meeting the SkipConstrainCheck option.
• Handle binary data in the HEX function and the unhex function.
• Return ErrNoDB (No database selected) when no database is used and the table name is without database qualifier.

Improved

• Refactor optimiser:
  • Prune ordered column paths.
  • Prepare for using the new CBO framework.
• Flatten the row operations.
• Log critical statements.
• Code clean up.

New contributor

sempr JackDrogon Zhang Jian

Weekly update in TiKV

Last week, We landed 12 PRs in the TiKV repositories.

Added

• Use the bi-directional stream for PD region heartbeat.
• Add the selection executor for coprocessor.
• Support the read committed isolation level for transactions.
• Add the modify function for JSON document.

Fixed

• Use Equal to check parsed timestamp.
• Fix the heartbeat tests.

Improved

• Generate snapshot concurrently.
• Skip handling read only commands in the Raft apply worker.
• Upgrade Rust Protobuf to the 1.4 version.