Weekly update in TiDB

Last week, we landed 49 PRs in the TiDB repository.

Added

• Propose the window function design
• Introduce a new join reorder framework in the DP-subset algorithm
• Add a document about online DDL architecture

Improved

• Try PointGetPlan when the plan cache is enabled
• Make a query plan containing non-deterministic functions cacheable
• Add validation check when setting the max_allowed_packet system variable
• Use module of Go 1.11 for dependency management
• Impose check when adding the foreign key
• Eliminate ifnull() if the argument can never be null
• Convert IN subquery to Aggregation with the inner join

Fixed

• Specially handle HOUR in date arithmetic functions
• Treat _tidb_rowid conditions of index scan as index filters
• Avoid using columnEvaluator for Projection built by buildProjtion4Union
• Fix selectivity estimation inaccuracy for non-integer primary key
• Fix wrong index resolution for PhysicalIndexReader
• Fix a panic caused by the wrong default value for table information_schema.profiling
• Fix a panic caused by nil Backoff.vars
• Fix a panic caused by type mismatch in SHOW COLUMNS
• Refine ResolveIndices for sequential Projections to avoid panics
• Fix a panic caused by type mismatch in UPDATE
• Avoid precision loss when casting JSON to decimal
• Reset the statement context before PREPARE to avoid panics
• Change the privilege component to use Auth* portion of identity

Weekly update in TiSpark

Last week, we landed 5 PRs in the TiSpark repository.

Added

• Support cache table commands

Weekly update in TiKV and PD

Last week, we landed 5 PRs in the TiKV and PD repositories.

Added

• Support the SubstringIndex function in Coprocessor

Improved

• Make pdctl escape the key before querying the corresponding Region

New contributors (Thanks!)

tidb:

• iamzhoug37
• imiskolee

docs:

• ppiao

docs-cn:

• exialin

tidb-operator:

• anywhy