releases, TOC: add release notes for 2.1.12 (#1220)

* releases, TOC: add release notes for 2.1.12

* Add a release note

TOC.md

@@ -326,6 +326,7 @@
     - [3.0.0-beta.1](releases/3.0.0-beta.1.md)
     - [3.0.0-beta](releases/3.0beta.md)
   + v2.1
+    - [2.1.12](releases/2.1.12.md)
     - [2.1.11](releases/2.1.11.md)
     - [2.1.10](releases/2.1.10.md)
     - [2.1.9](releases/2.1.9.md)

releases/2.1.12.md

@@ -0,0 +1,44 @@
+---
+title: TiDB 2.1.12 Release Notes
+category: Releases
+---
+
+# TiDB 2.1.12 Release Notes
+
+Release date: June 13, 2019
+
+TiDB version: 2.1.12
+
+TiDB Ansible version: 2.1.12
+
+## TiDB
+
+- Fix the issue caused by unmatched data types when using the index query feedback [#10755](https://github.com/pingcap/tidb/pull/10755)
+- Fix the issue that the blob column is changed to the text column caused by charset altering in some cases [#10745](https://github.com/pingcap/tidb/pull/10745)
+- Fix the issue that the `GRANT` operation in the transaction mistakenly reports "Duplicate Entry" in some cases [#10739](https://github.com/pingcap/tidb/pull/10739)
+- Improve the compatibility with MySQL of the following features
+    - The `DAYNAME` function [#10732](https://github.com/pingcap/tidb/pull/10732)
+    - The `MONTHNAME` function [#10733](https://github.com/pingcap/tidb/pull/10733)
+    - Support the 0 value for the `EXTRACT` function when processing `MONTH` [#10702](https://github.com/pingcap/tidb/pull/10702)
+    - The `DECIMAL` type can be converted to `TIMESTAMP` or `DATETIME` [#10734](https://github.com/pingcap/tidb/pull/10734)
+- Change the column charset while changing the table charset [#10714](https://github.com/pingcap/tidb/pull/10714)
+- Fix the overflow issue when converting a decimal to a float in some cases [#10730](https://github.com/pingcap/tidb/pull/10730)
+- Fix the issue that some extremely large messages report the "grpc: received message larger than max" error caused by inconsistent maximum sizes of messages sent/received by gRPC of TiDB and TiKV [#10710](https://github.com/pingcap/tidb/pull/10710)
+- Fix the panic issue caused by `ORDER BY` not filtering NULL in some cases [#10488](https://github.com/pingcap/tidb/pull/10488)
+- Fix the issue that values returned by the `UUID` function might be duplicate when multiple nodes exist [#10711](https://github.com/pingcap/tidb/pull/10711) 
+- Change the value returned by `CAST(-num as datetime)` from `error` to NULL [#10703](https://github.com/pingcap/tidb/pull/10703) 
+- Fix the issue that an unsigned histogram meets signed ranges in some cases [#10695](https://github.com/pingcap/tidb/pull/10695)
+- Fix the issue that an error is reported mistakenly for reading data when the statistics feedback meets the bigint unsigned primary key [#10307](https://github.com/pingcap/tidb/pull/10307)
+- Fix the issue that the result of `Show Create Table` for partitioned tables is not correctly displayed in some cases [#10690](https://github.com/pingcap/tidb/pull/10690)
+- Fix the issue that the calculation result of the `GROUP_CONCAT` aggregate function is not correct for some correlated subqueries [#10670](https://github.com/pingcap/tidb/pull/10670)
+- Fix the issue that the result is wrongly displayed when the memory table of slow queries parses the slow query log in some cases [#10776](https://github.com/pingcap/tidb/pull/10776)
+
+## PD
+
+- Fix the issue that etcd leader election is blocked in extreme conditions
+[#1576](https://github.com/pingcap/pd/pull/1576)
+
+## TiKV
+
+- Fix the issue that Regions are not available during the leader transfer process in extreme conditions [#4799](https://github.com/tikv/tikv/pull/4734)
+- Fix the issue that TiKV loses data when the power of the machine fails abnormally, caused by delayed data flush to the disk when receiving snapshots [#4850](https://github.com/tikv/tikv/pull/4850)

releases/rn.md

@@ -14,6 +14,7 @@ category: release
 
 ## 2.1
 
+- [2.1.12](../releases/2.1.12.md)
 - [2.1.11](../releases/2.1.11.md)
 - [2.1.10](../releases/2.1.10.md)
 - [2.1.9](../releases/2.1.9.md)