TiDB Weekly

Community

New contributors

tidb:

• mmyj
• js00070
• ZhaoQian888
• justarandomstring
• XiaTianliang
• rogaps

parser:

• tsthght

Call for participation

• Redefine System Variables with Golang type

• Vectorized Expression Working Group

  • Date or Time built-in functions (11/65)
  • Decimal built-in functions (9/31)
  • Int built-in functions (55/187)
  • JSON built-in functions (3/27)
  • Real built-in functions (38/49)
  • String built-in functions (32/133)
  • Duration built-in functions (5/45)
  • Total Progress (153/537)
  • 67 PRs are landed in the expression component

• Other issues to solve in TiDB

• Other issues to solve in TiKV

Updates of the week

Progress

Last week, we landed 132 PRs in the TiDB repository, 6 PRs in the TiSpark repository, 45 PRs in the TiKV and PD repositories.

Critical PRs

TiDB:

• Fix bugs for the shallow copy
• Fix the issue that KV requests might be processed slower because the connection to some KV servers is slow to establish
• Refactor the ResolveLocks() function for the implementation of large transactions
• Eliminate the unnecessary pessimistic rollback
• Make the IndexHashJoin support keep the outer order
• Fix the permanent hanging when HashAgg is called by Apply
• Support IndexLookUpMergeJoin in the executor
• Support splitting Regions for the partition table
• Add the json_valid built-in function
• Make the selection executor support the vectorized expression evaluation
• Record and print the plan in slow logs
• Support automatically creating SQL baselines
• Disable the constant propagation for AntiSemiJoin
• Introduce the preprocessing phase in the cascades planner
• Fix a compatibility issue that if the foreign key constraint in the CREATE TABLE statement has no schema, schema of the created table should be used instead of returning the No Database selected error
• Check whether the column type in the range column partitioning table and the value type of the less than xxx expression in partition are consistent
• Fix the CREATE TABLE check for the range column partition
• Avoid writing the untouched index in the auto-commit transaction and avoid getting the untouched index key from TiKV

TiSpark:

• Fix a bug in the default value of the Bit type
• Fix the cost model

TiKV and PD:

• Fix the issue that the blob file is missing in Titan
• Fix the issue that check_txn_status does not write the rollback record when the key does not exist
• Protect the primary locks of pessimistic transactions from being collapsed
• Decouple the GC worker from storage
• Fix the data race issue when cloning StoreInfo
• Support the balance leader according to the leader count

Upcoming TiDB events

TiDB Hackathon 2019 (in Chinese)

• Time: 26th to 27th October, 2019 (UTC/GMT+08:00)
• Location: PingCAP offices in Beijing, Shanghai and Guangzhou