TiDB RC1 Release Notes

On December 23, 2016, TiDB RC1 is released. See the following updates in this release:

TiKV

• The write speed has been improved.
• The disk space usage is reduced.
• Hundreds of TBs of data can be supported.
• The stability is improved and TiKV can support a cluster with 200 nodes.
• Supports the Raw KV API and the Golang client.

Placement Driver (PD)

• The scheduling strategy framework is optimized and now the strategy is more flexible and reasonable.
• The support for label is added to support Cross Data Center scheduling.
• PD Control is provided to operate the PD cluster more easily.

TiDB

• The following features are added or improved in the SQL query optimizer:
  • Eager aggregation
  • More detailed EXPLAIN information
  • Parallelization of the UNION operator
  • Optimization of the subquery performance
  • Optimization of the conditional push-down
  • Optimization of the Cost Based Optimizer (CBO) framework
• The implementation of the time related data types are refactored to improve the compatibility with MySQL.
• More built-in functions in MySQL are supported.
• The speed of the add index statement is enhanced.
• The following statements are supported:
  • Use the CHANGE COLUMN statement to change the name of a column.
  • Use MODIFY COLUMN and CHANGE COLUMN of the ALTER TABLE statement for some of the column type transfer.

New tools

• Loader is added to be compatible with the mydumper data format in Percona and provides the following functions:
  • Multi-thread import
  • Retry if error occurs
  • Breakpoint resume
  • Targeted optimization for TiDB
• The tool for one-click deployment is added.