2017-10-09-tidb-weekly.md

title	date	summary	tags
Weekly update (September 25 ~ October 08, 2017)	2017-10-09	Last two weeks, we landed 62 PRs in the TiDB repositories and 39 PRs in the TiKV repositories.	TiDB TiKV TiSpark

Weekly update in TiDB

Last two weeks, we landed 62 PRs in the TiDB repositories.

Added

• Support the SyncLog Key-Value request option.
• Support the NotFillCache Key-Value request option.
• Support the combination SQL modes.

Removed

• Close the aggregation pushdown by default and remove the CBO switch.
• Remove some useless code.
• Remove the usage of TypeClass completely.

Fixed

• Change the like function to be case sensitive.
• Prepare to enforce errcheck, step 1.
• Make the prepare statement retry when the schema is out-dated.
• Revoke etcd on ctx.Done to prevent the situation that no owner entry left.
• Pre-calculate the lower and upper scalar.
• Add length limitation for index comment.
• Make insert with calculated value behave the same as MySQL.
• Drop invalid cached region.

Improved

• Turn on the analyze statement pushdown switch.
• Upgrade pd-client to fix a bug.
• Rewrite the unit test for Minus and Plus functions.
• The analyze statement uses NewSelectResult.
• Remove the usage of evalExprToXXX functions to improve performance.
• Change structured slow log to friendly JSON output.
• Refactor parser step 2: to be compatible with MySQL syntax.
• Refactor the SelectDAG function parameter.
• Speed up the add index operation.
• Optimize the SortExec executor.
• Split separated region for newly created table.
• Change the schema validator data structure to queue.
• Change the way of transferring the handle.
• Support more signatures pushdown.

Weekly update in TiSpark

Added

• Add the Configuration Framework

Fixed

• Fix invalid leader store ID cases
• Remove unused parameter for TiSpark context during the startup

Weekly update in TiKV

Last two weeks, We landed 39 PRs in the TiKV repositories.

Added

• Use expression in DAG.
• Namespace isolation: http interface and classifier.
• Report read statistics to PD.
• Pushdown sampling: implement histogram.
• Support ppc64le.
• Pushdown the analyze request.
• Support the must_sync flag for raft ready.
• Introduce Disconnected and LowSpace states for store.
• Add an API to compact a range for the specified column family.

Fixed

• Stop the thread pool on shutdown.
• Fix block send problem in grpc.
• Fix potential unreachable drop.
• Fix tablecodec.

Improved

• Select response of DAG don’t need row meta.
• Add drop message metrics.
• Debug: implement size.
• Debug: implement region information.
• Add slow log for applying.
• Update gRPC to 1.6.1.
• Check whether peers need to split after initialization.
• Refactor Key-Value for PD.
• Config: change all the names to kebab-case](tikv/pd#772).
• Flush the leader message as soon as possible.
• Return error instead of panic if an expression is illegal.
• Update etcd to v3.2.6 for PD.
• Synchronize data before applying snapshots.
• Update the client URLs continuously.
• Adjust the region heartbeat metrics.

New contributors

• Priya Seth