TiDB 2.0.5 Release Notes

On July 6, 2018, TiDB 2.0.5 is released. Compared with TiDB 2.0.4, this release has great improvement in system compatibility and stability.

TiDB

• New Features
  • Add the tidb_disable_txn_auto_retry system variable which is used to disable the automatic retry of transactions #6877
• Improvements
  • Optimize the cost calculation of Selection to make the result more accurate #6989
  • Select the query condition that completely matches the unique index or the primary key as the query path directly #6966
  • Execute necessary cleanup when failing to start the service #6964
  • Handle \N as NULL in the Load Data statement #6962
  • Optimize the code structure of CBO #6953
  • Report the monitoring metrics earlier when starting the service #6931
  • Optimize the format of slow queries by removing the line breaks in SQL statements and adding user information #6920
  • Support multiple asterisks in comments #6858
• Bug Fixes
  • Fix the issue that KILL QUERY always requires SUPER privilege #7003
  • Fix the issue that users might fail to login when the number of users exceeds 1024 #6986
  • Fix an issue about inserting unsigned float/double data #6940
  • Fix the compatibility of the COM_FIELD_LIST command to resolve the panic issue in some MariaDB clients #6929
  • Fix the CREATE TABLE IF NOT EXISTS LIKE behavior #6928
  • Fix an issue in the process of TopN pushdown #6923
  • Fix the ID record issue of the currently processing row when an error occurs in executing Add Index #6903

PD

• Fix the issue that replicas migration uses up TiKV disks space in some scenarios
• Fix the crash issue caused by AdjacentRegionScheduler

TiKV

• Fix the potential overflow issue in decimal operations
• Fix the dirty read issue that might occur in the process of merging