2017-05-22-tidb-weekly.md

title	date	summary	tags
Weekly update (May 15 ~ May 21, 2017)	2017-05-22	Last week, we landed 31 PRs in the TiDB repositories and 16 PRs in the TiKV repositories.	TiDB TiKV

Weekly update in TiDB

Last week, we landed 31 PRs in the TiDB repositories.

Added

• Use etcd to elect DDL job leader.

• Support Load Data with specified column list.

• Add the following builtin functions:

  • umcompress and uncompressdlength
  • convert_tz
  • period-diff

• Support the Json type and Json data encoding/decoding.

• Add a Jenkins CI in Pull Request.

• Add the EvalDuration and EvalTime interface for expressions.

• Support Index Lookup Join in new planner.

Fixed

• Add default value for the Password Validation system variables.

• Fix the issue of retrying with no limitation when committing primary key failed.

• Fix the issue of context cancellation triggering onSendFail and dropping cache: context cancel doesn't mean cache out of data.

• Fix a bug in Sort Merge Join.

• Correct comment mistakes.

• Reprocess SQL statement when meeting the infoschema change error.

• Update an error code to MySQL standard error code.

• Consider schema changing when retrying prepared statement.

Improved

• Refator range calculation related code.

• Consider task type when building the physical plan: to make cost more precise.

• Support more SQL grammar for Lock Options.

• Rename SupportRequestType to IsRequestTypeSupported to improve readability.

• Support more SQL grammar for Compress Options in the AlterTable statement.

• Change the schema of statistic table.

Weekly update in TiKV

Last week, We landed 16 PRs in the TiKV repositories.

Added

• Support table scan with DAG in coprocessor.
• Add Jenkins support, see 643, 644, 1835, 1836.
• Write Raft log synchronously to ensure data safety.

Fixed

• Use IEC size for size output.
• Enlarge max duration for scheduler histogram metrics.

Improved

• Use SmallGroupFirstQueue in endpoint scheduler.
• Fetch snapshot lazily to reduce the cost of creating unnecessary snapshot.
• Create WriteBatch with capacity to avoid reallocating.