releases: add v4.0.9 release notes

TOC.md

@@ -529,6 +529,7 @@
   + [All Releases](/releases/release-notes.md)
   + [TiDB Roadmap](/roadmap.md)
   + v4.0
+    + [4.0.9](/releases/release-4.0.9.md)
     + [4.0.8](/releases/release-4.0.8.md)
     + [4.0.7](/releases/release-4.0.7.md)
     + [4.0.6](/releases/release-4.0.6.md)

releases/release-4.0.9.md

@@ -0,0 +1,122 @@
+---
+title: TiDB 4.0.9 Release Notes
+---
+
+# TiDB 4.0.9 Release Notes
+
+Release date: December 3, 2020
+
+TiDB version: 4.0.9
+
+## New Features
+
++ TiFlash
+
+    - Support multi-disks for storing latest data [#1159](https://github.com/pingcap/tics/pull/1159)
+
+## Improvements
+
+
+
+## Bug Fixes
+
++ TiDB
+
+    - Fix incorrect results when using a prefix index with OR condition [#21287](https://github.com/pingcap/tidb/pull/21287)
+    - Fix a bug cause panic when retry is enable. [#21285](https://github.com/pingcap/tidb/pull/21285)
+    - Fix a bug that checks partition definition according to column type [#21273](https://github.com/pingcap/tidb/pull/21273)
+    - Fix a bug that hash type partition does not check partition name is unique [#21257](https://github.com/pingcap/tidb/pull/21257)
+    - Fix unexpected error when `INSERT` meets index join in some cases. [#21249](https://github.com/pingcap/tidb/pull/21249)
+    - Fix insert value into hash partition table which not int [#21238](https://github.com/pingcap/tidb/pull/21238)
+    - Fix Bigint unsigned column value in CASE WHEN operator is converted to bigint signed #9869 [#21236](https://github.com/pingcap/tidb/pull/21236)
+    - Fix a bug that index-hash-join and index-merge-join doesn't consider collation [#21219](https://github.com/pingcap/tidb/pull/21219)
+    - Fix issue of the query result of slow_query maybe miss some rows. [#21211](https://github.com/pingcap/tidb/pull/21211)
+    - `DELETE` may not delete data correctly when the database name is not in pure lower representation. [#21206](https://github.com/pingcap/tidb/pull/21206)
+    - Raise an error when preparing the `load data` statement. [#21199](https://github.com/pingcap/tidb/pull/21199)
+    - Fix a bug that partition table does not consider collation in `create table` and `select` sentence. [#21181](https://github.com/pingcap/tidb/pull/21181)
+    - Disallow multi-updates on primary key [#21113](https://github.com/pingcap/tidb/pull/21113)
+    - Fix a bug causes schema change after DML [#21050](https://github.com/pingcap/tidb/pull/21050)
+    - Fix the bug that can not query the coalesced column when use using-join. [#21021](https://github.com/pingcap/tidb/pull/21021)
+    - Fix wrong results for some semi join queries. [#21019](https://github.com/pingcap/tidb/pull/21019)
+    - Fix table lock for update statement. [#21002](https://github.com/pingcap/tidb/pull/21002)
+    - Fix stack overflow when building recursive view. [#21001](https://github.com/pingcap/tidb/pull/21001)
+    - Ddl: ignore integer zerofill size attribute when changing the column types [#20986](https://github.com/pingcap/tidb/pull/20986)
+    - Fix unexpected results when do merge join on outer join [#20954](https://github.com/pingcap/tidb/pull/20954)
+    - Fix the issue that sometimes a transaction that has undetermined result may be treated as failed. [#20925](https://github.com/pingcap/tidb/pull/20925)
+
++ PD
+
+    - Fix the issue that the leader role does not take effect when using the replacement rule in some cases [#3208](https://github.com/pingcap/pd/pull/3208)
+    - Fix the bug that `trace-region-flow` will be accidentally changed to `false`. [#3120](https://github.com/pingcap/pd/pull/3120)
+
++ TiFlash
+
+    - Fix the problem that `INFORMATION_SCHEMA.CLUSTER_HARDWARE` may contain information about disks not in use. [#1248](https://github.com/pingcap/tics/pull/1248)
+    - Fix the issue that the memory consumption statistic of Delta Cache is smaller than actual usage. [#1212](https://github.com/pingcap/tics/pull/1212)
+
+## Others
+
++ TiDB
+
+    - Fix issue of explain for connection can't show the last query plan/ [#21315](https://github.com/pingcap/tidb/pull/21315)
+    - Add metric for connection idle time [#21301](https://github.com/pingcap/tidb/pull/21301)
+    - Fix the issue that when Index Merge is used in a transaction with RC isolation level, the result may be incorrect. [#21253](https://github.com/pingcap/tidb/pull/21253)
+    - Planner: fix wrong point get plan generation in fast plan code path [#21244](https://github.com/pingcap/tidb/pull/21244)
+    - Expression: keep the original data type when doing date arithmetic operations [#21176](https://github.com/pingcap/tidb/pull/21176)
+    - Ban (index) merge join heuristically when convert equal conditions to other conditions. [#21146](https://github.com/pingcap/tidb/pull/21146)
+    - Ddl: Fix partition table's partition column values type check [#21136](https://github.com/pingcap/tidb/pull/21136)
+    - Make dump binary time more compatible with MySQL [#21135](https://github.com/pingcap/tidb/pull/21135)
+    - Differentiate types for user variables [#21107](https://github.com/pingcap/tidb/pull/21107)
+    - Fix auto-id allocation failed because of transaction's write-conflict retry. [#21079](https://github.com/pingcap/tidb/pull/21079)
+    - Fix The JSON Data can not import to TiDB correctly by `load data` [#21074](https://github.com/pingcap/tidb/pull/21074)
+    - Fix up displaying executor runtime info & Add runtime information for DML in explain analyze [#21066](https://github.com/pingcap/tidb/pull/21066)
+    - Deprecate `enable-streaming`. [#21055](https://github.com/pingcap/tidb/pull/21055)
+    - Avoid unnecessary warnings/errors when folding constants in shortcut-able expressions [#21040](https://github.com/pingcap/tidb/pull/21040)
+    - TiDB now provides an error for statements that use the syntax `LOCK IN SHARE MODE`. This helps alert users that this feature is not implemented by TiDB, but a workaround to restore the previous behavior is available by setting `tidb_enable_noop_functions=1`. [#21005](https://github.com/pingcap/tidb/pull/21005)
+    - Set correct default value for new added enum column. [#20998](https://github.com/pingcap/tidb/pull/20998)
+    - Allow set GOGC in config file. [#20922](https://github.com/pingcap/tidb/pull/20922)
+
++ TiKV
+
+    - Fix a bug that Coprocessor may return wrong result when there are > 255 columns. [#9131](https://github.com/tikv/tikv/pull/9131)
+    - Fix an issue that region merge may cause data loss during network partition. [#9108](https://github.com/tikv/tikv/pull/9108)
+    - Enable dynamically change config pessimistic-txn.pipelined. [#9100](https://github.com/tikv/tikv/pull/9100)
+    - Running checksum in BR and Lightning should have less influence on the cluster performance. [#9098](https://github.com/tikv/tikv/pull/9098)
+    - Revert "encryption: Turn file dictionary into log style" [#9097](https://github.com/tikv/tikv/pull/9097)
+    - Add a metrics for ingest sst errors [#9096](https://github.com/tikv/tikv/pull/9096)
+    - Prevent hibernation when there are still peers catching up logs [#9093](https://github.com/tikv/tikv/pull/9093)
+    - Increase the success rate of pipelined pessimistic locking. [#9086](https://github.com/tikv/tikv/pull/9086)
+    - Fix a bug may cause analyze statement panic when using the latin1 character set. [#9082](https://github.com/tikv/tikv/pull/9082)
+    - Config: fix invalid advertise-status-addr [#9036](https://github.com/tikv/tikv/pull/9036)
+    - Fix cast decimal as time expr get wrong result when deal with numbers argument [#9031](https://github.com/tikv/tikv/pull/9031)
+    - Add check to avoid corruption due to RocksDB block cache error #8243. Also disable `force-consistency-checks` by default to improve performance. [#9029](https://github.com/tikv/tikv/pull/9029)
+    - Change the default value of `apply-max-batch-size` and `store-max-batch-size` to 1024. [#9020](https://github.com/tikv/tikv/pull/9020)
+    - Fix the bug that lightning fails to ingest sst files to tikv with importer/local backend when TDE is enabled [#8995](https://github.com/tikv/tikv/pull/8995)
+    - Turn file dictionary into log style. [#8960](https://github.com/tikv/tikv/pull/8960)
+    - Add config for max-background-flushes [#8947](https://github.com/tikv/tikv/pull/8947)
+    - Add tag to split command to trace its source [#8936](https://github.com/tikv/tikv/pull/8936)
+    - Fix the issue that reports a key-exist error when a key is locked and deleted by a committed transaction. [#8930](https://github.com/tikv/tikv/pull/8930)
+    - Enable the unified read pool for the storage module by default. [#8887](https://github.com/tikv/tikv/pull/8887)
+
++ PD
+
+    - Dashboard: update to v2020.11.26.1 [#3219](https://github.com/pingcap/pd/pull/3219)
+    - Check cluster version on stores become tombstone [#3213](https://github.com/pingcap/pd/pull/3213)
+    - The store of lower version is no longer allowed to change from `Tombstone` back to `Up`. [#3206](https://github.com/pingcap/pd/pull/3206)
+    - Fix a bug that service safe points with  infinite TTL may disappear. [#3143](https://github.com/pingcap/pd/pull/3143)
+
++ TiFlash
+
+    - Implement `batch_read_index` to reduce latency about replica read. [#1236](https://github.com/pingcap/tics/pull/1236)
+    - Refine TiFlash's error message [#1231](https://github.com/pingcap/tics/pull/1231)
+    - Limit the memory usage of cache data under huge volume data. [#1229](https://github.com/pingcap/tics/pull/1229)
+    - > [#1227](https://github.com/pingcap/tics/pull/1227)
+    - Add metric "number of handling cop task". [#1183](https://github.com/pingcap/tics/pull/1183)
+
++ Tools
+
+    - TiCDC
+
+        * Metrics: add alert for tikv hibernate regions [#1120](https://github.com/pingcap/ticdc/pull/1120)
+        * Fix the bug that multiple owners could exist when owner campaign key is deleted [#1104](https://github.com/pingcap/ticdc/pull/1104)
+        * Kafka_consumer: fix wrong timezone when 'TZ' env is not set and downstream is mysql [#1095](https://github.com/pingcap/ticdc/pull/1095)

releases/release-notes.md

@@ -7,6 +7,7 @@ aliases: ['/docs/dev/releases/release-notes/','/docs/dev/releases/rn/']
 
 ## 4.0
 
+- [4.0.9](/releases/release-4.0.9.md)
 - [4.0.8](/releases/release-4.0.8.md)
 - [4.0.7](/releases/release-4.0.7.md)
 - [4.0.6](/releases/release-4.0.6.md)