2018-01-22-tidb-weekly.md

title	date	summary	tags
Weekly update (January 15 ~ January 21, 2018)	2018-01-22	Last week, we landed 43 PRs in the TiDB repositories, 13 PRs in the TiSpark repositories, and 18 PRs in the TiKV and PD repositories.	TiDB TiSpark TiKV PD

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