align 4 PR from docs-cn (#10808)

TOC.md

@@ -659,6 +659,7 @@
       - [`SHOW COLLATION`](/sql-statements/sql-statement-show-collation.md)
       - [`SHOW [FULL] COLUMNS FROM`](/sql-statements/sql-statement-show-columns-from.md)
       - [`SHOW CONFIG`](/sql-statements/sql-statement-show-config.md)
+      - [`SHOW CREATE DATABASE`](/sql-statements/sql-statement-show-create-database.md)
       - [`SHOW CREATE PLACEMENT POLICY`](/sql-statements/sql-statement-show-create-placement-policy.md)
       - [`SHOW CREATE SEQUENCE`](/sql-statements/sql-statement-show-create-sequence.md)
       - [`SHOW CREATE TABLE`](/sql-statements/sql-statement-show-create-table.md)

functions-and-operators/miscellaneous-functions.md

@@ -32,7 +32,5 @@ TiDB supports most of the [miscellaneous functions](https://dev.mysql.com/doc/re
 
 | Name | Description  |
 |:------------|:-----------------------------------------------------------------------------------------------|
-| [`GET_LOCK()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock)                | Get a named lock [TiDB #10929](https://github.com/pingcap/tidb/issues/14994) |
-| [`RELEASE_LOCK()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_release-lock)        | Releases the named lock [TiDB #10929](https://github.com/pingcap/tidb/issues/14994) |
 | [`UUID_SHORT()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_uuid-short)            | Provides a UUID that is unique given certain assumptions not present in TiDB [TiDB #4620](https://github.com/pingcap/tidb/issues/4620) |
 | [`MASTER_WAIT_POS()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_master-pos-wait)  | Relates to MySQL replication |

information-schema/information-schema-tidb-indexes.md

@@ -28,8 +28,10 @@ DESC tidb_indexes;
 | INDEX_COMMENT | varchar(2048) | YES  |      | NULL    |       |
 | Expression    | varchar(64)   | YES  |      | NULL    |       |
 | INDEX_ID      | bigint(21)    | YES  |      | NULL    |       |
+| IS_VISIBLE    | varchar(64)   | YES  |      | NULL    |       |
+| CLUSTERED     | varchar(64)   | YES  |      | NULL    |       |
 +---------------+---------------+------+------+---------+-------+
-10 rows in set (0.00 sec)
+12 rows in set (0.00 sec)
 ```
 
 `INDEX_ID` is the unique ID that TiDB allocates for each index. It can be used to do a join operation with `INDEX_ID` obtained from another table or API.
@@ -59,4 +61,6 @@ Fields in the `TIDB_INDEXES` table are described as follows:
 * `COLUMN_NAME`: The name of the column where the index is located.
 * `SUB_PART`: The prefix length of the index. If the the column is partly indexed, the `SUB_PART` value is the count of the indexed characters; otherwise, the value is `NULL`.
 * `INDEX_COMMENT`: The comment of the index, which is made when the index is created.
-* `INDEX_ID`: The index ID.
+* `INDEX_ID`: The index ID.
+* `IS_VISIBLE`: Whether the index is visible.
+* `CLUSTERED`: Whether it is a [clustered index](/clustered-indexes.md).

sql-statements/sql-statement-alter-table.md

@@ -49,6 +49,11 @@ AlterTableSpec ::=
 |   'SECONDARY_UNLOAD'
 |   ( 'AUTO_INCREMENT' | 'AUTO_ID_CACHE' | 'AUTO_RANDOM_BASE' | 'SHARD_ROW_ID_BITS' ) EqOpt LengthNum
 |   ( 'CACHE' | 'NOCACHE' )
+|   PlacementPolicyOption
+
+PlacementPolicyOption ::=
+    "PLACEMENT" "POLICY" EqOpt PolicyName
+|   "PLACEMENT" "POLICY" (EqOpt | "SET") "DEFAULT"
 ```
 
 ## Examples

sql-statements/sql-statement-create-database.md

@@ -21,6 +21,17 @@ DBName ::=
 
 DatabaseOptionListOpt ::=
     DatabaseOptionList?
+
+DatabaseOptionList ::=
+    DatabaseOption ( ','? DatabaseOption )*
+
+DatabaseOption ::=
+    DefaultKwdOpt ( CharsetKw '='? CharsetName | 'COLLATE' '='? CollationName | 'ENCRYPTION' '='? EncryptionOpt )
+|   DefaultKwdOpt PlacementPolicyOption
+
+PlacementPolicyOption ::=
+    "PLACEMENT" "POLICY" EqOpt PolicyName
+|   "PLACEMENT" "POLICY" (EqOpt | "SET") "DEFAULT"
 ```
 
 ## Syntax

sql-statements/sql-statement-create-table.md

@@ -82,9 +82,14 @@ TableOption ::=
 |   'SECONDARY_ENGINE' EqOpt ( 'NULL' | StringName )
 |   'UNION' EqOpt '(' TableNameListOpt ')'
 |   'ENCRYPTION' EqOpt EncryptionOpt
+|   PlacementPolicyOption
 
 OnCommitOpt ::=
     ('ON' 'COMMIT' 'DELETE' 'ROWS')?
+
+PlacementPolicyOption ::=
+    "PLACEMENT" "POLICY" EqOpt PolicyName
+|   "PLACEMENT" "POLICY" (EqOpt | "SET") "DEFAULT"
 ```
 
 The following *table_options* are supported. Other options such as `AVG_ROW_LENGTH`, `CHECKSUM`, `COMPRESSION`, `CONNECTION`, `DELAY_KEY_WRITE`, `ENGINE`, `KEY_BLOCK_SIZE`, `MAX_ROWS`, `MIN_ROWS`, `ROW_FORMAT` and `STATS_PERSISTENT` are parsed but ignored.

sql-statements/sql-statement-show-create-database.md

@@ -0,0 +1,64 @@
+---
+title: SHOW CREATE DATABASE
+summary: An overview of the use of SHOW CREATE DATABASE in the TiDB database.
+---
+
+# SHOW CREATE DATABASE
+
+`SHOW CREATE DATABASE` is used to show the exact SQL statement for re-creating an existing database. `SHOW CREATE SCHEMA` is a synonym for it.
+
+## Synopsis
+
+**ShowCreateDatabaseStmt:**
+
+```ebnf+diagram
+ShowCreateDatabaseStmt ::=
+    "SHOW" "CREATE" "DATABASE" | "SCHEMA" ("IF" "NOT" "EXISTS")? DBName
+```
+
+## Examples
+
+```sql
+CREATE DATABASE test;
+```
+
+```sql
+Query OK, 0 rows affected (0.12 sec)
+```
+
+```sql
+SHOW CREATE DATABASE test;
+```
+
+```sql
++----------+------------------------------------------------------------------+
+| Database | Create Database                                                  |
++----------+------------------------------------------------------------------+
+| test     | CREATE DATABASE `test` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ |
++----------+------------------------------------------------------------------+
+1 row in set (0.00 sec)
+```
+
+```sql
+SHOW CREATE SCHEMA IF NOT EXISTS test;
+```
+
+```sql
++----------+-------------------------------------------------------------------------------------------+
+| Database | Create Database                                                                           |
++----------+-------------------------------------------------------------------------------------------+
+| test     | CREATE DATABASE /*!32312 IF NOT EXISTS*/ `test` /*!40100 DEFAULT CHARACTER SET utf8mb4 */ |
++----------+-------------------------------------------------------------------------------------------+
+1 row in set (0.00 sec)
+```
+
+## MySQL compatibility
+
+`SHOW CREATE DATABASE` is expected to be fully compatible with MySQL. If you find any compatibility differences, submit a GitHub [issue](https://github.com/pingcap/tidb/issues/new/choose).
+
+## See also
+
+* [CREATE TABLE](/sql-statements/sql-statement-create-table.md)
+* [DROP TABLE](/sql-statements/sql-statement-drop-table.md)
+* [SHOW TABLES](/sql-statements/sql-statement-show-tables.md)
+* [SHOW COLUMNS FROM](/sql-statements/sql-statement-show-columns-from.md)