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

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