TiDB 1.1 Beta Release Notes

On February 24, 2018, TiDB 1.1 Beta is released. This release has great improvement in MySQL compatibility, SQL optimization, stability, and performance.

TiDB:

  • Add more monitoring metrics and refine the log
  • Compatible with more MySQL syntax
  • Support displaying the table creating time in information_schema
  • Optimize queries containing the MaxOneRow operator
  • Configure the size of intermediate result sets generated by Join, to further reduce the memory used by Join
  • Add the tidb_config session variable to output the current TiDB configuration
  • Fix the panic issue in the Union and Index Join operators
  • Fix the wrong result issue of the Sort Merge Join operator in some scenarios
  • Fix the issue that the Show Index statement shows indexes that are in the process of adding
  • Fix the failure of the Drop Stats statement
  • Optimize the query performance of the SQL engine to improve the test result of the Sysbench Select/OLTP by 10%
  • Improve the computing speed of subqueries in the optimizer using the new execution engine; compared with TiDB 1.0, TiDB 1.1 Beta has great improvement in tests like TPC-H and TPC-DS

PD:

  • Add the Drop Region debug interface
  • Support setting priority of the PD leader
  • Support configuring stores with a specific label not to schedule Raft leaders
  • Add the interfaces to enumerate the health status of each PD
  • Add more metrics
  • Keep the PD leader and the etcd leader together as much as possible in the same node
  • Improve the priority and speed of restoring data when TiKV goes down
  • Enhance the validity check of the data-dir configuration item
  • Optimize the performance of Region heartbeat
  • Fix the issue that hot spot scheduling violates label constraint
  • Fix other stability issues

TiKV:

  • Traverse locks using offset + limit to avoid potential GC problems
  • Support resolving locks in batches to improve GC speed
  • Support GC concurrency to improve GC speed
  • Update the Region size using the RocksDB compaction listener for more accurate PD scheduling
  • Delete the outdated data in batches using DeleteFilesInRanges, to make TiKV start faster
  • Configure the Raft snapshot max size to avoid the retained files taking up too much space
  • Support more recovery operations in tikv-ctl
  • Optimize the ordered flow aggregation operation
  • Improve metrics and fix bugs