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• Delete the outdated data in batches using DeleteFilesInRanges, to make TiKV start faster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