2017-06-20-tidb-weekly.md

title	date	summary	tags
Weekly update (June 12 ~ June 18, 2017)	2017-06-20	Last week, we landed 30 PRs in the TiDB repositories and 14 PRs in the TiKV repositories.	TiDB TiKV

Weekly update in TiDB

Last week, we landed 30 PRs in the TiDB repositories.

Added

• Refactor the optimizer:
  • Refactor ranger/statistic: calculate the range and row count of non pk column.
• JSON type:
  • Support generated column:](pingcap/tidb#3431)
  • Support the JSON type in the cast expression.
• Generated column:
  • Support basic generated column.
  • Prevent modifying generated column.
  • Add GeneratedExpr in ColumnInfo.
• Support using clause in join statement.
• Use GetTSAsync api from pd-client.
• Support SubTime.

Fixed

• Fix a bug in alter table statement.
• Fix a bug in cast.
• Fix a bug about parsing Duration literal.
• Fix a divide zero bug in statistic.
• Fix a protobuf unmarshal related bug in coprocessor.
• Fix a bug about auto_increment column conflict after renaming table.

Improved

• Add some columns in mysql.user: compatiable with MySQL.
• Use multiple grpc connnections for each store: improve performance.
• Refactor expression evaluation:
  • Consider unsigned flag in cast expression.
• Speed up DDL process:
  • Revoke the etcd-session when ddl worker is closed.

Weekly update in TiKV

Last week, We landed 14 PRs in the TiKV repositories.

Added

• Coprocessor supports index scan executor.
• Add MySQL JSON type.
• Support comparison for mySQL JSON type.

Fixed

• Fix a bug caused by GC with stale command.

Improved

• Increase initialized window size to 2MB for gRPC stream.
• Using prefix_same_as_start to optimize seek for Write CF.
• Use multiple connections to speed up Raft message sending.
• Update Dockerfile, see 1915 and 1919.

New contributor

• AkihiroSuda