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