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Delete the outdated data in batches using DeleteFilesInRanges, to make TiKV start faster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