Weekly update in TiDB

Last week, we landed 37 PRs in the TiDB repository.

Added

• Implement ALTER DATABASE to alter the charset/collation
• Support the incremental and repeats importer columns

Improved

• Disable the new @@wait_timeout feature
• Improve the package test code coverage to above 85% in util/codec
• Make the resolveLock phase of GC concurrent to improve its speed
• Always set isPessimisticLock in the request for pessimistic transactions
• Use multiple indexes to scan a table if possible
• Refine transaction retry error messages
• Reduce the wait backoff time when the lock has expired

Fixed

• Fix a time format error in ParseSlowLog
• Fix the issue that the RANGE frame has no ORDER BY clause in the Window function
• Fix the inconsistency problem by prohibiting modifying decimal precision
• Fix a bug when an unsigned histogram meets signed ranges in the feedback
• Fix the issue that period_diff is not compatible with MySQL 8.0
• Fix the wrong range calculation for the CHAR column
• Fix the issue that the type of the add_date result is not compatible with MySQL
• Fix the float overflow issue when converting a decimal to a float and then converting a float to an uint

Weekly update in TiSpark

Last week, we landed 19 PRs in the TiSpark repository.

Fixed

• Fix the concurrent dagRequest issue
• Fix the behavior of downgrading to a table scan when performing an index scan

Weekly update in TiKV and PD

Last week, we landed 24 PRs in the TiKV and PD repositories.

Added

• Add the explain analyze support for the aggregation executor
• Add the summary support for the Top-N executor
• Set timeout for MoveLeader
• Support the execution summary for the selection executor
• Add the ScanRegions gRPC protocol in PD

Fixed

• Do not collect requests that read indexes during transferring the leader
• Reject transferring the leader when the Region's configuration is recently changed

Improved

• Handle system commands in the high priority pool
• Make most ticks lazy in TiKV
• Use tokio_threadpool for the transaction scheduler
• Speed up Docker building and remove unused files

New contributors (Thanks!)

tikv:

• andrisak

tidb:

• hailanwhu
• jzdxeb

docs-cn:

• spongedu