Weekly update in TiDB

Last week, we landed 43 PRs in the TiDB repositories.

Added

• Add an interface for Chunk to count the memory usage
• Add a session variable to log the query string

Removed

• Remove the old, never used IndexLookUpJoin

Fixed

• group_concat should not modify the argument during execution
• Correct the unsigned pk's behavior

Improved

• Optimize the com_field_list command and make Use Database faster
• Improve the sort efficiency on lookupTableTask.rows
• Enlarge the default distsql_scan_concurrency
• Log a warning when the memory usage of HashJoinExec exceeds threshhold
• Refine the behavior when updating StatsDelta
• Split the presentation and evaluation layers of aggregation functions
• Use BatchGet to speed up LOAD DATA

Weekly update in TiSpark

Last week, we landed 13 PRs in the TiSpark repositories.

Improved

• Refactor the type and expression systems totally
  • Reorganize the type and expressions
  • Use the visitor instead of raw expressions when processing traversal
  • Fixed type infer logics
  • Refactor predicates processing logic according to the visitor pattern
  • Fixed index encoding
• Change CodecDataInput to use non-synchronized ByteArrayInputStream
• Add TiKV, PD, and TiDB's config files for Docker test environment

Weekly update in TiKV and PD

Last week, we landed 18 PRs in the TiKV and PD repositories.

Added

• simulator: add hot region cases

Fixed

• proto: compatible with proto3
• heartbeat: rebind the stream
• server: delete overlap from etcd

Improved

• Refactor the raftstore Callback API
• Remove the unused rocksdb.backup_dir
• Adjust Scheduler metrics
• impl Runnable for Scheduler