2017-08-14-tidb-weekly.md

layout	title
post	Weekly Update

Weekly update in TiDB

2017-08-14

Last week, we landed 78 PRs in the TiDB repositories.

Added

• Enable pushing down the following operations to TiKV.
  • the JSON function
  • ifnull
  • minus and multiply
• Use the Delete-in-Range feature to speed up the Drop Database/Table/Index operations.
• Support prioritizing statements.

Fixed

• Fix the TimeDiff compatibility issue.
• Consider charset in Right/Left/Substr.
• Do not record metrics when running intenal SQL.
• Fix potential issue of schema validation check.
• Add desc order info in explain.

Improved

• Refactor the row structure to reduce memory allocation.
• Refactor the following expressions/builtin-functions evaluation framework:
  • Plus
  • Multiply
  • Minus
  • lpad/rpad
  • bin
  • from_base64
  • char
  • reverse
  • ifnull
  • instr
  • aes_encrypt/aes_decrypt
  • is_true/is_false
  • locate
  • last_insert_id
  • compress/uncompress/uncompress_length
  • sleep
  • conv
  • char_length
  • md5/sha1/sha2
  • charactor_length
  • elt
  • ifnull
  • if
  • round/abs
  • random_bytes
  • unaryplus
• Adjust cost for the Sort operator.
• Change the row format from structure to Datum slice.

Weekly update in TiKV

Last week, We landed 28 PRs in the TiKV repositories.

Added

• Add hex/escaped converting for tikv-ctl.
• Add custom instant for time utilities.
• Add rows properties.
• Add size properties.
• Add region approximate size.
• Support basic DAG expression evaluation for coprocessor.
• Support the delete range KV command.
• Add the diff command for tikv-ctl to check the difference between 2 databases.

Fixed

• Fix a bug caused by using box_try for the coprocessor.

Improved

• Speed up clearing meta.
• Reduce callback by batching RaftCmdRequest.
• Refactor the configuration.
• Refactor the DAG and old selection.
• Refactor the time utilities.