On March 15, 2019, TiDB 2.1.6 is released. The corresponding TiDB Ansible 2.1.6 is also released. Compared with TiDB 2.1.5, this release has greatly improved the stability, the SQL optimizer, statistics, and the execution engine.
IndexScancannot be selected correctly in some cases #9587
aggfunction in subqueries #9551
show stats_histogramsonly output valid columns to avoid panics #9502
protobufparsing failure would in some cases cause a
region-split-sizeof importer to 512 MiB #4369