releases: add tidb 5.0.2 release notes

TOC.md

@@ -539,6 +539,7 @@
   + [All Releases](/releases/release-notes.md)
   + [TiDB Roadmap](/roadmap.md)
   + v5.0
+    + [5.0.2](/releases/release-5.0.2.md)
     + [5.0.1](/releases/release-5.0.1.md)
     + [5.0 GA](/releases/release-5.0.0.md)
     + [5.0.0-rc](/releases/release-5.0.0-rc.md)

releases/release-5.0.2.md

@@ -0,0 +1,111 @@
+---
+title: TiDB 5.0.2 Release Notes
+---
+
+# TiDB 5.0.2 Release Notes
+
+Release date: June 9, 2021
+
+TiDB version: 5.0.2
+
+## Compatibility Changes
+
+## New Features
+
+## Improvements
+
++ TiDB
+
+    - Skip reading mysql.stats_histograms if cached stats is up-to-date [#24317](https://github.com/pingcap/tidb/pull/24317)
+
++ TiFlash
+
+    - Apply Region snapshots by ingesting files to reduce memory usage
+    - Optimize the table lock to avoid reading and DDL jobs blocking each other
+    - Support casting the integer or real type to real type
+
+## Bug Fixes
+
++ TiDB
+
+    - Fix index join panic on prefix index on some cases [#24824](https://github.com/pingcap/tidb/pull/24824)
+    - Fix the issue point get cached plan of prepared statement is incorrectly used by in transaction point get statement. [#24765](https://github.com/pingcap/tidb/pull/24765)
+    - Fix write wrong prefix index value when collation is ascii_bin/latin1_bin [#24680](https://github.com/pingcap/tidb/pull/24680)
+    - Fix the issue that ongoing transaction could be aborted by the gc worker. [#24652](https://github.com/pingcap/tidb/pull/24652)
+    - Fix bug that point query maybe get wrong on the clustered index when new-collation enabled but new-row-format disabled [#24611](https://github.com/pingcap/tidb/pull/24611)
+    - Refactor converting partition keys for shuffle hash join [#24490](https://github.com/pingcap/tidb/pull/24490)
+    - Fix panic when building plan for a query containing HAVING clause. [#24489](https://github.com/pingcap/tidb/pull/24489)
+    - Planner: fix column pruning bug for Apply and Join [#24437](https://github.com/pingcap/tidb/pull/24437)
+    - Fix the bug that primary lock fallen back from async commit cannot be resolved. [#24397](https://github.com/pingcap/tidb/pull/24397)
+    - Statistics: fix a statistics GC problem that can cause duplicated fm-sketch records [#24357](https://github.com/pingcap/tidb/pull/24357)
+    - Avoid unnecessary pessimistic rollback when pessimistic locking receives ErrKeyExists [#23800](https://github.com/pingcap/tidb/pull/23800)
+    - Fix numeric literals cannot be recognized when set 'ANSI_QUOTES' sql_mode [#25015](https://github.com/pingcap/tidb/pull/25015)
+    - No longer allowing `INSERT INTO table PARTITION (<partitions>) ... ON DUPLICATE KEY UPDATE` to read from non-listed partitions [#25000](https://github.com/pingcap/tidb/pull/25000)
+    - Fix "index out of range" error when a SQL contains both group by and union. [#24551](https://github.com/pingcap/tidb/pull/24551)
+    - Fix wrong collation for concat function [#24301](https://github.com/pingcap/tidb/pull/24301)
+    - Fix global variable collation_server does not take effect in new session [#24156](https://github.com/pingcap/tidb/pull/24156)
+
++ TiFlash
+
+    - Fix the issue of incorrect results when cloning shared delta index concurrently
+    - Fix the potential issue that TiFlash fails to restart with incomplete data
+    - Fix the issue that old dm files are not removed atomically
+    - Fix the potential panic that occurs when feature `compaction filter` is enabled
+    - Fix the potential issue that `ExchangeSender` will send duplicated chunks
+    - Fix the issue that TiFlash can not resolve fallen back `async commit` lock
+    - Fix the issue of incorrect results when the return columns of casting timezone contains timestamp type
+    - Fix the issue that TiFlash panics during Segment Split
+    - Fix the issue that execution information about non root MPP task is not accurate
+
++ Tools
+
+    - Backup & Restore (BR)
+
+        - Fix the bug that batch split region fails due to total key size exceeds raft entry limit [#1148](https://github.com/pingcap/br/pull/1148)
+
+## 以下 note 未分类。请将以下 note 进行分类 (New feature, Improvements, Bug fixes, Compatibility Changes 四类)，并移动到上面对应的标题下。如果某条 note 为多余的，请删除。如果漏抓取了 note，请手动补充
+
++ TiKV
+
+    - release-note [#10278](https://github.com/tikv/tikv/pull/10278)
+    - Enable hibernate regions by default (i.e. `raftstore.hibernate-regions = true`). [#10266](https://github.com/tikv/tikv/pull/10266)
+    - Fix CDC OOM issue caused by reading old values. [#10246](https://github.com/tikv/tikv/pull/10246)
+    - BR now supports S3-compatible storage using virtual-host addressing style. [#10243](https://github.com/tikv/tikv/pull/10243)
+    - Fix read empty value for the clustered primary key column in the secondary index when collation is latin1_bin. [#10239](https://github.com/tikv/tikv/pull/10239)
+    - Add `abort-on-panic` config, which allow core dump to be generated when panic. Users still need to correctly config the environment to enable core dump. [#10216](https://github.com/tikv/tikv/pull/10216)
+    - Support ingesting default-cf and write-cf sst in one raft command. [#10202](https://github.com/tikv/tikv/pull/10202)
+    - Support back pressure CDC scan speed. [#10151](https://github.com/tikv/tikv/pull/10151)
+    - Reduce memory usage of CDC initial scan. [#10133](https://github.com/tikv/tikv/pull/10133)
+    - Fix sysbench point-get performance regression when TiKV readpool is not busy. [#10115](https://github.com/tikv/tikv/pull/10115)
+    - Improve CDC old value cache hit ratio in pessimistic txn [#10089](https://github.com/tikv/tikv/pull/10089)
+    - Approximate split range evenly [#10086](https://github.com/tikv/tikv/pull/10086)
+
++ PD
+
+    - Fix offline_stats statistic after merge offline peer [#3615](https://github.com/pingcap/pd/pull/3615)
+
++ Tools
+
+    + Backup & Restore (BR)
+
+        - Fix the issue that restore from `mysql` schema would failed. [#1143](https://github.com/pingcap/br/pull/1143)
+        - BR would check cluster version of backup now. [#1091](https://github.com/pingcap/br/pull/1091)
+        - Fix the issue that log restore lost delete key during restore. [#1083](https://github.com/pingcap/br/pull/1083)
+        - BR now support backing up user tables created in the `mysql` schema. [#1078](https://github.com/pingcap/br/pull/1078)
+        - Fix a bug that caused, when backup failed, nothing would be printed to terminal. [#1043](https://github.com/pingcap/br/pull/1043)
+        - Fix a bug that caused BR send too many useless RPCs to TiKV [#1037](https://github.com/pingcap/br/pull/1037)
+
+    - TiCDC
+
+        - Add metrics for table memory consumption [#1885](https://github.com/pingcap/ticdc/pull/1885)
+        - Owner:  When tikv_gc_life_time is greater than gcttl, use tikv_gc_life_time to calculate the lower bound of gcSafePoint. [#1872](https://github.com/pingcap/ticdc/pull/1872)
+        - Reduce memory malloc in sort heap to avoid too much CPU overhead. [#1863](https://github.com/pingcap/ticdc/pull/1863)
+        - Flow Control bug fix (no released version affected) [#1859](https://github.com/pingcap/ticdc/pull/1859)
+        - Support sink flow control to reduce OOM [#1840](https://github.com/pingcap/ticdc/pull/1840)
+        - Fix a bug about resolved ts stopped when move a table. [#1828](https://github.com/pingcap/ticdc/pull/1828)
+        - Fix a deadlock bug in the kv client that deadlock happens when large stale regions exist. [#1801](https://github.com/pingcap/ticdc/pull/1801)
+        - Modified the update strategy of gcSafePoint.  Fix the problem that TiKV GC safe point is blocked indefinitely due to TiCDC changefeed checkpoint stagnation. [#1759](https://github.com/pingcap/ticdc/pull/1759)
+        - Revert the update for explicit_defaults_for_timestamp which requires `SUPER` privilege when replicating to MySQL. [#1750](https://github.com/pingcap/ticdc/pull/1750)
+        - Add stale temporary files clean-up in Unified Sorter, and forbids sharing sort-dir. [#1742](https://github.com/pingcap/ticdc/pull/1742)
+        - Add http handler for failpoint [#1733](https://github.com/pingcap/ticdc/pull/1733)
+        - Fix time zone lost in Avro output. [#1712](https://github.com/pingcap/ticdc/pull/1712)

releases/release-notes.md

@@ -7,6 +7,7 @@ aliases: ['/docs/dev/releases/release-notes/','/docs/dev/releases/rn/']
 
 ## 5.0
 
+- [5.0.2](/releases/release-5.0.2.md)
 - [5.0.1](/releases/release-5.0.1.md)
 - [5.0 GA](/releases/release-5.0.0.md)
 - [5.0.0-rc](/releases/release-5.0.0-rc.md)