update tidb v4.0.12 release notes

TOC.md

@@ -528,6 +528,7 @@
   + v5.0
     + [5.0.0-rc](/releases/release-5.0.0-rc.md)
   + v4.0
+    + [4.0.12](/releases/release-4.0.12.md)
     + [4.0.11](/releases/release-4.0.11.md)
     + [4.0.10](/releases/release-4.0.10.md)
     + [4.0.9](/releases/release-4.0.9.md)

releases/release-4.0.12.md

@@ -0,0 +1,117 @@
+---
+title: TiDB 4.0.12 Release Notes
+---
+
+# TiDB 4.0.12 Release Notes
+
+Release date: March 31, 2021
+
+TiDB version: 4.0.12
+
+## New Features
+
++ TiFlash
+
+    - Add tools to check exact tiflash replica status for online rolling update [#1512](https://github.com/pingcap/tics/pull/1512)
+
+## Improvements
+
++ TiFlash
+
+    - Automatically clean archive data to free up disk space [#1638](https://github.com/pingcap/tics/pull/1638)
+    - Allow omitting deprecated "users.*" settings in the configuration file of TiFlash. [#1535](https://github.com/pingcap/tics/pull/1535)
+    - Reduce the size of TiFlash binary file. [#1414](https://github.com/pingcap/tics/pull/1414)
+
+## Bug Fixes
+
++ TiDB
+
+    - Fix get var expr when session var is hex literal [#23372](https://github.com/pingcap/tidb/pull/23372)
+    - Fix the bug that wrong collation is used when try fast path for enum or set [#23292](https://github.com/pingcap/tidb/pull/23292)
+    - Wrong result of nullif expr when used with is null expr [#23279](https://github.com/pingcap/tidb/pull/23279)
+    - Statistics: fix a case that auto-analyze is triggered outside its time range [#23219](https://github.com/pingcap/tidb/pull/23219)
+    - Executor: fix cast function will ignore the error for point get key construction [#23211](https://github.com/pingcap/tidb/pull/23211)
+    - Fixed a bug that prevented SPM from taking effect [#23209](https://github.com/pingcap/tidb/pull/23209)
+    - Fix wrong table filters for index merge plan [#23165](https://github.com/pingcap/tidb/pull/23165)
+    - Fix unexpected NotNullFlag in case when expr ret type [#23135](https://github.com/pingcap/tidb/pull/23135)
+    - Fix a bug that collation is not handle for text type [#23092](https://github.com/pingcap/tidb/pull/23092)
+    - Fix range partition prune bug for IN expr [#23074](https://github.com/pingcap/tidb/pull/23074)
+    - Fix request block forever when replace a tombstone store with the store has same IP addr [#23071](https://github.com/pingcap/tidb/pull/23071)
+    - Scattering truncated tables without pre-split option. [#22872](https://github.com/pingcap/tidb/pull/22872)
+    - Do not ajust int when it is null and compared year [#22844](https://github.com/pingcap/tidb/pull/22844)
+    - Add three format specifier for str_to_date expression [#22812](https://github.com/pingcap/tidb/pull/22812)
+    - Fix load data lost connection error on tables with auto_random column [#22736](https://github.com/pingcap/tidb/pull/22736)
+    - Record prepare execute fail as "Failed Query OPM" in monitor [#22672](https://github.com/pingcap/tidb/pull/22672)
+    - Do not report error for prepared stmt execution if tidb_snapshot is set [#22641](https://github.com/pingcap/tidb/pull/22641)
+
++ PD
+
+    - Save to the region cache when pending-peers or down-peers change [#3471](https://github.com/pingcap/pd/pull/3471)
+    - Checker: prevent the regions in split-cache from becoming the target of merge [#3459](https://github.com/pingcap/pd/pull/3459)
+
++ TiFlash
+
+    - Fix the issue that binary type column's default value containing leading zero bytes is trimmed and does not contain padded tailing zero bytes [#1571](https://github.com/pingcap/tics/pull/1571)
+    - Fix the bug that TiFlash fail to sync schema if the database name contains special character [#1559](https://github.com/pingcap/tics/pull/1559)
+    - Use an adaptive aggressive data GC strategy to avoid OOM [#1553](https://github.com/pingcap/tics/pull/1553)
+    - Fix wrong result of IN function [#1532](https://github.com/pingcap/tics/pull/1532)
+    - Fix the bug that opened file count shown in Grafana is high [#1503](https://github.com/pingcap/tics/pull/1503)
+    - Support timestamp literal in dag requeset [#1501](https://github.com/pingcap/tics/pull/1501)
+    - Fix potential segmentation fault in TiFlash [#1491](https://github.com/pingcap/tics/pull/1491)
+    - Fix problem CastStringAsInt may produce wrong result. [#1481](https://github.com/pingcap/tics/pull/1481)
+    - Fix a bug that the `like` function may return wrong result [#1461](https://github.com/pingcap/tics/pull/1461)
+
++ Tools
+
+    - BR
+
+        * Fix the bug that lightning generated ts may be to large or small that query may return incorrect result. [#860](https://github.com/pingcap/br/pull/860)
+        * No release note (it's not released yet.) [#854](https://github.com/pingcap/br/pull/854)
+        * Fix the bug that importer may ignore write rows error if open engine returns `file exists` error [#848](https://github.com/pingcap/br/pull/848)
+
+## 请判断下面未分类 note，对下面 note 进行分类并移动到以上三个分类部分中
+
++ TiDB
+
+    - Fix ddl hang over when it meets panic in cancelling path. [#23297](https://github.com/pingcap/tidb/pull/23297)
+    - Refine explain info for batch cop [#23164](https://github.com/pingcap/tidb/pull/23164)
+    - Fix wrong key range of index scan when filter is comparing year column with NULL [#23104](https://github.com/pingcap/tidb/pull/23104)
+    - Fix create view success but failed when using it [#23083](https://github.com/pingcap/tidb/pull/23083)
+    - Add warning info for exprs that can not be pushed to storage layer for explain statement. [#23020](https://github.com/pingcap/tidb/pull/23020)
+    - Ddl: migrate part of ddl package code from Execute/ExecRestricted to safe API (2) [#22935](https://github.com/pingcap/tidb/pull/22935)
+    - Ddl: migrate part of ddl package code from Execute/ExecRestricted to safe API (1). [#22929](https://github.com/pingcap/tidb/pull/22929)
+    - Add optimization-time and wait-TS-time into the slow log [#22918](https://github.com/pingcap/tidb/pull/22918)
+    - Support query partition_id from infoschema.partitions [#22489](https://github.com/pingcap/tidb/pull/22489)
+    - Add 'last_plan_from_binding' to help know whether sql's plan is matched with the hints in the binding [#21430](https://github.com/pingcap/tidb/pull/21430)
+
++ TiKV
+
+    - Pd_client: prevent a large number of reconnections in a short time [#9879](https://github.com/tikv/tikv/pull/9879)
+    - Fix IN expr(coprocessor) didn't handle unsigned/signed int properly [#9850](https://github.com/tikv/tikv/pull/9850)
+    - Fix the issue that ingests operation cannot reentrant. [#9779](https://github.com/tikv/tikv/pull/9779)
+    - Optimize seek write for many tombstones [#9729](https://github.com/tikv/tikv/pull/9729)
+    - Fix missing space when casting json to string in TiKV coprocessor [#9666](https://github.com/tikv/tikv/pull/9666)
+    - Change the default `leader-transfer-max-log-lag` to 128 to increase the success rate of leader transfer [#9605](https://github.com/tikv/tikv/pull/9605)
+
++ PD
+
+    - Fix the bug that the isolation level is wrong when the store lacks label [#3474](https://github.com/pingcap/pd/pull/3474)
+
++ Tools
+
+    - BR
+
+        * Reduce memory usage during backup. [#886](https://github.com/pingcap/br/pull/886)
+        * Added configurations `tikv-importer.engine-mem-cache-size` and `tikv-importer.local-writer-mem-cache-size` to tune between memory usage and performance. [#866](https://github.com/pingcap/br/pull/866)
+        * BR would log `HTTP_PROXY` and `HTTPS_PROXY` now. [#827](https://github.com/pingcap/br/pull/827)
+        * Add cluster_version and br_version info in backupmeta [#803](https://github.com/pingcap/br/pull/803)
+        * Check TiDB cluster version before running TiDB-Lightning to avoid unexpected errors. [#787](https://github.com/pingcap/br/pull/787)
+        * Improve backup performance when there are many tables. [#745](https://github.com/pingcap/br/pull/745)
+
+    - TiCDC
+
+        * Fix a data loss bug when capture restarts due to network issue, and some table on it is scheduled at the same time. [#1523](https://github.com/pingcap/ticdc/pull/1523)
+        * Add double confirm when creating or resuming changefeed with `start-ts` or `checkpoint-ts` 1 day before current ts. [#1499](https://github.com/pingcap/ticdc/pull/1499)
+        * No release note, the bug is never released [#1475](https://github.com/pingcap/ticdc/pull/1475)
+        * Fix a resolved ts event disorder problems caused by concurrency [#1472](https://github.com/pingcap/ticdc/pull/1472)
+        * No release note, this bug is never released [#1470](https://github.com/pingcap/ticdc/pull/1470)

releases/release-notes.md

@@ -11,6 +11,7 @@ aliases: ['/docs/dev/releases/release-notes/','/docs/dev/releases/rn/']
 
 ## 4.0
 
+- [4.0.12](/releases/release-4.0.12.md)
 - [4.0.11](/releases/release-4.0.11.md)
 - [4.0.10](/releases/release-4.0.10.md)
 - [4.0.9](/releases/release-4.0.9.md)