TiDB 2.0 RC4 Release Notes

On March 30, 2018, TiDB 2.0 RC4 is released. This release has great improvement in MySQL compatibility, SQL optimization and stability.

TiDB

• Support SHOW GRANTS FOR CURRENT_USER();
• Fix the issue that the Expression in UnionScan is not cloned
• Support the SET TRANSACTION syntax
• Fix the potential goroutine leak issue in copIterator
• Fix the issue that admin check table misjudges the unique index including null
• Support displaying floating point numbers using scientific notation
• Fix the type inference issue during binary literal computing
• Fix the issue in parsing the CREATE VIEW statement
• Fix the panic issue when one statement contains both ORDER BY and LIMIT 0
• Improve the execution performance of DecodeBytes
• Optimize LIMIT 0 to TableDual, to avoid building useless execution plans

PD

• Support splitting Region manually to handle the hot spot in a single Region
• Fix the issue that the label property is not displayed when pdctl runs config show all
• Optimize metrics and code structure

TiKV

• Limit the memory usage during receiving snapshots, to avoid OOM in extreme conditions
• Support configuring the behavior of Coprocessor when it encounters warnings
• Support importing the data pattern in TiKV
• Support splitting Region in the middle
• Increase the speed of CI test
• Use crossbeam channel
• Fix the issue that too many logs are output caused by leader missing when TiKV is isolated