2017-06-12-tidb-weekly.md

layout	title
post	Weekly Update

Weekly update in TiDB

2017-06-12

Last week, we landed 52 PRs in the TiDB repositories.

Added

• Refactor the optimizer:

  • Add an statsProfile interface to propagate statistic information among plans.
  • Implement the statsProfile interface for the Join plan.

• JSON type:

  • Suport json_set, json_insert, json_replace and json_merge.
  • Support the JSON type in the cast expression.

• Use gRPC between TiDB and TiKV.

• Refactor the Analyze executor.

• Add the SubDuration function in util package.

• Support the generated column grammar.

Fixed

• Create a session when the current session with etcd expires.

• Fix a bug about padding zeros for binary data.

• Fix a bug about type inference.

• Fix a but about data access race.

• Avoid allocating too much memory in the top-n operator.

• Add timeout when getting TimeStamp.

• Make the behavior of read-only transactions using the SelectForUpdate statement consistent with MySQL.

Improved

• Refactor expression evaluation:

  • Add builtinAddTimeSig
  • Correct cast function implementation.
  • Clean up code and prepare to add test cases.
  • Implement wrap expression with the cast expression.

• Speed up DDL process:

  • Extract interfaces for OwnerManger and SchemaSyncer. Add mock implementation for unit test.
  • Add TTL for DDL related keys on etcd.

• Code style clean up.

Weekly update in TiKV

Last week, We landed 25 PRs in the TiKV repositories.

Added

• Add the bloom filter for Lock CF meltable.
• Introduce gRPC, see 1892, 1894, 1896, 1903
• Use SST based bloom filter by default.
• Remove the bloom filter for Raft CF.
• Provide the GetTSAsync API.

Fixed

• Delete idle snapshot only on GC.
• Notify the blocked goroutines when get stream error.
• Fix a bug in get_txn_commit_info for concurrent prewrite.
• Check the leader again when fail to create TSO stream.
• Fix a data race problem in PD client.

Improved

• Optimize the Raft log entry fetching.
• Capture the SIGHUP and close gracefully.
• Avoid allocating lots of memory in topn function.
• Use SST snapshot format by default to speed up Raft snapshot applying.