2017-07-17-tidb-weekly.md

title	date	summary	tags
Weekly update (July 10 ~ July 16, 2017)	2017-07-17	Last week, we landed 51 PRs in the TiDB repositories and 23 PRs in the TiKV repositories.	TiDB TiKV

Weekly update in TiDB

Last week, we landed 51 PRs in the TiDB repositories.

Added

• Support setting variables with ON and OFF.
• Support show stats_histgrams and show stats_buckets for debugging.
• Support the Scan API for the raw KV interface.
• Support the Show Charset statement.
• Support user name without quotes such as [email protected].

Fixed

• Fix a bug when explicitly inserting the null value into columns with the timestamp type.
• Do not check privileges for the information_schema database.
• Correct the error message for the authentication error.
• Fix a bug in the cast function with an unsigned type.

Improved

• Refactor optimizer:
  • Select Join operator by CBO framework automatically: #3623, #3737, #3761
  • Use statsProfile to estimate count and cardinality.
• Refactor the builtin function evaluation framework:
  • left & right
  • lower & upper
  • concat_ws
  • to_base64
  • md5
  • space
  • replace
  • substring/substr
  • compare
  • uuid
  • bit_length
  • log10
  • Move the type inference work from typeinfer to expression rewritter: aggregate expression, column & constant expression
• Close the connection after sending ERR_Packet.
• Improve the unit test coverage for parser packages.

Weekly update in TiKV

Last week, We landed 23 PRs in the TiKV repositories.

Added

• Add json_modify, math function evaluators for the coprocessor.
• Pass the compression type to generate snapshot SST.
• Set 256 MB as the default region size.
• Add the raw Scan API.

Fixed

• Ignore the command that removes the leader itself.
• Fix diff hint overflow.
• Rotate PD log by default.
• Fix the leap second problem in Go 1.9.
• Clean up stale metadata when start.

Improved

• Reduce the lock scope for region heartbeat.
• Send the raft messages in batch.
• Refactor the coprocessor code directory.
• Enable the pipelined write.
• Remove unnecessary hash group keys.