Weekly update in TiDB

Last week, we landed 45 PRs in the TiDB repositories.

Added

• Add hints to force to choose HashJoin.
• Provide the HTTP API of table disk usage for tidb-ctl.

Fixed

• Fix a bug when updating the JSON field.
• Delete the auto ID key when renaming the table.
• Fix a bug in JoinResultGenerator.
• Fix a bug when backfilling the index with nil.
• The value of a session variable should not be modified when getting a global variable.

Improved

• Move the Cancel function from session to clientConn.
• Reduce a comparison in the union scan.
• Move the binary-tree library from petar/GoLLRB to google/btree.
• Add the Format interface on ExprNode to convert AST back to string.
• Improve the performance of ShowVariables.
• Add Chunk/List to hold a slice of Chunk.
• Add the explain info for TopN.
• Support coprocessor streaming API for the TiKV client.
• Support sql_mode IGNORE SPACE.
• Support the builtin aggregation function bit_xor.
• Refactor SQL query optimizer:
  • Replace Sort with LogicalSort and PhysicalSort.
  • Add Physical operator for Lock, Limit and UnionAll.
  • Make Show no longer a logical/physical plan.
  • Add Physical plan for MaxOneRow, Dual and Exists.
  • Add Physical plan for Projection and TopN.
  • Extract getChildrenPossibleProp to a file.
  • Add PhysicalStreamAgg and remove AggType.
• Support Chunk in executors:
  • InsertExec
  • MaxOneRowExec
  • TopN
  • UnionExec

Weekly update in TiSpark

Last week, we landed 12 PRs in the TiSpark repositories.

Added

• Implement the Coprocessor DAG mode reading.
• Implement TopN pushdown.
• Add the switch for disabling a specific expression pushdown for old versions of TiKV.
• Add the Cache invalidation notification for the client.

Fixed

• Fix the reading error when all values in group aggregate to null.
• Fix a potential error escape from Handler.
• Fix inconsistent PD cache eviction and add capture for leaked exception.
• Fix the pushdown type problem of timestamp.

Weekly update in TiKV and PD

Last week, we landed 21 PRs in the TiKV and PD repositories.

Added

• Add TiltCase and Main.
• Support lower_bound for iterator.
• Add on_tick for BatchRunnable.
• Support getting the unique index.
• Add role_observer in the coprocessor.
• Record the wait time of APPLY_TASK.
• Support disabling the block cache for test.
• Support setting bytes_per_sync and wal_bytes_per_sync.

Fixed

• Use the same configuration for tikv-ctl and tikv-server.
• Fix zero truncation in decimal decoding.
• Call the post_apply hook.
• Support the TLS connection in pd-recover.

Improved

• Improve scheduler metrics.
• Avoid cloning prs in Raft.
• Update Limiter using all pending operators.
• Use a bit field to present the operator kind.
• Update RocksDB with optimized ingesting SST.
• Reduce the log in the MVCC layer.
• Refactor tests for the RPC client.
• Optimize the dev build and fix typo.

New contributors (Thanks!)

• TiDB:
  • Evgeniy Kulikov
  • denofiend
• docs-cn:
  • Guangkuo Bian