Weekly update (September 05 ~ September 11, 2016)

Last week, we landed 20 PRs in the TiDB repositories and 32 PRs in the TiKV repositories..

Notable changes to TiDB

• Support mydumper
• Use MySQL standard error code in the DDL execution results
• Use heap sort operator to handle the statements with Limit and Orderby
• Add support for the CLIENT_CONNECT_ATTRS
• Add the constant propagation support to the SQL optimizer
• Optimize the [index scan executor] (https://github.com/pingcap/tidb/pull/1696) to improve the performance
• Optimize the distributed SQL API protocol to improve the performance
• Fix several bugs.

Notable changes to TiKV

• Add the divide operation support to Coprocessor.
• Switch to the prometheus metrics from the statsd metrics.
• Abort applying the snapshot if it conflicts with a new one to fix 1014.
• Ensure that the data from the last write before the GC Safe-Point time can't be removed to fix 1021.
• Add the document for Scheduler.
• Calculate the used space correctly.
• Stop GC scan if there are no keys left to fix the endless-loop problem.

Notable changes to Placement Driver

• Support store removing gracefully.
• Add the Admin API.
• Reduce the default min-capacity-used-ratio value for an earlier auto-balance.