pingcap · morgo · Jun 25, 2019 · Jun 25, 2019 · Jun 25, 2019 · Jun 25, 2019
diff --git a/dev/reference/sql/functions-and-operators/bit-functions-and-operators.md b/dev/reference/sql/functions-and-operators/bit-functions-and-operators.md
@@ -6,7 +6,7 @@ category: reference
 
 # Bit Functions and Operators
 
-In TiDB, the usage of bit functions and operators is similar to MySQL. See [Bit Functions and Operators](https://dev.mysql.com/doc/refman/5.7/en/bit-functions.html).
+TiDB supports all of the [bit functions and operators](https://dev.mysql.com/doc/refman/5.7/en/bit-functions.html) available in MySQL 5.7.
 
 **Bit functions and operators**
 

diff --git a/dev/reference/sql/functions-and-operators/cast-functions-and-operators.md b/dev/reference/sql/functions-and-operators/cast-functions-and-operators.md
@@ -6,6 +6,7 @@ category: reference
 
 # Cast Functions and Operators
 
+TiDB supports all of the [cast functions and operators](https://dev.mysql.com/doc/refman/5.7/en/cast-functions.html) available in MySQL 5.7.
 
 | Name                                     | Description                      |
 | ---------------------------------------- | -------------------------------- |
@@ -14,5 +15,3 @@ category: reference
 | [`CONVERT()`](https://dev.mysql.com/doc/refman/5.7/en/cast-functions.html#function_convert) | Cast a value as a certain type   |
 
 Cast functions and operators enable conversion of values from one data type to another.
-
-For details, see [here](https://dev.mysql.com/doc/refman/5.7/en/cast-functions.html).
diff --git a/dev/reference/sql/functions-and-operators/control-flow-functions.md b/dev/reference/sql/functions-and-operators/control-flow-functions.md
@@ -6,6 +6,8 @@ category: reference
 
 # Control Flow Functions
 
+TiDB supports all of the [control flow functions](https://dev.mysql.com/doc/refman/5.7/en/control-flow-functions.html) available in MySQL 5.7.
+
 | Name                                                                                            | Description                       |
 |:--------------------------------------------------------------------------------------------------|:----------------------------------|
 | [`CASE`](https://dev.mysql.com/doc/refman/5.7/en/control-flow-functions.html#operator_case)       | Case operator                     |

diff --git a/dev/reference/sql/functions-and-operators/date-and-time-functions.md b/dev/reference/sql/functions-and-operators/date-and-time-functions.md
@@ -6,7 +6,7 @@ category: reference
 
 # Date and Time Functions
 
-The usage of date and time functions is similar to MySQL. For more information, see [here](https://dev.mysql.com/doc/refman/5.7/en/date-and-time-types.html).
+TiDB supports all of the [date and time functions](https://dev.mysql.com/doc/refman/5.7/en/numeric-functions.html) available in MySQL 5.7.
 
 **Date/Time functions**
 

diff --git a/dev/reference/sql/functions-and-operators/encryption-and-compression-functions.md b/dev/reference/sql/functions-and-operators/encryption-and-compression-functions.md
@@ -6,6 +6,10 @@ category: reference
 
 # Encryption and Compression Functions
 
+TiDB supports most of the [encryption and compression functions](https://dev.mysql.com/doc/refman/5.7/en/encryption-functions.html) available in MySQL 5.7.
+
+## Supported functions
+
 | Name                                                                                                                                               | Description                                       |
 |:------------------------------------------------------------------------------------------------------------------------------------------------------|:--------------------------------------------------|
 | [`MD5()`](https://dev.mysql.com/doc/refman/5.7/en/encryption-functions.html#function_md5)                                                             | Calculate MD5 checksum                            |
@@ -27,3 +31,10 @@ category: reference
 | [`ASYMMETRIC_ENCRYPT()`](https://dev.mysql.com/doc/refman/5.7/en/enterprise-encryption-functions.html#function_asymmetric-encrypt)                    | Encrypt cleartext using private or public key     |
 | [`ASYMMETRIC_SIGN()`](https://dev.mysql.com/doc/refman/5.7/en/enterprise-encryption-functions.html#function_asymmetric-sign)                          | Generate signature from digest                    |
 | [`ASYMMETRIC_VERIFY()`](https://dev.mysql.com/doc/refman/5.7/en/enterprise-encryption-functions.html#function_asymmetric-verify)                      | Verify that signature matches digest              |
+
+## Unsupported functions
+
+* `DES_DECRYPT()`, `DES_ENCRYPT()`, `OLD_PASSWORD()`, `ENCRYPT()`: these functions were deprecated in MySQL 5.7 and removed in 8.0.
+* `VALIDATE_PASSWORD_STRENGTH()`
+* Functions only available in MySQL Enterprise [Issue #2632](^[[200~https://github.com/pingcap/tidb/issues/2632)
+
diff --git a/dev/reference/sql/functions-and-operators/information-functions.md b/dev/reference/sql/functions-and-operators/information-functions.md
@@ -6,20 +6,28 @@ category: reference
 
 # Information Functions
 
-In TiDB, the usage of information functions is similar to MySQL. For more information, see [Information Functions](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html).
+TiDB supports most of the [information functions](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html) available in MySQL 5.7.
 
-## Information function descriptions
+## Supported functions
 
 | Name | Description |
 |:-----|:------------|
+| [`BENCHMARK()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_benchmark) | Execute an expression in a loop |
 | [`CONNECTION_ID()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_connection-id) | Return the connection ID (thread ID) for the connection  |
 | [`CURRENT_USER()`, `CURRENT_USER`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_current-user) | Return the authenticated user name and host name |
 | [`DATABASE()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_database) | Return the default (current) database name  |
 | [`FOUND_ROWS()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_found-rows) | For a `SELECT` with a `LIMIT` clause, the number of the rows that are returned if there is no `LIMIT` clause |
 | [`LAST_INSERT_ID()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_last-insert-id) | Return the value of the `AUTOINCREMENT` column for the last `INSERT`   |
+| [`ROW_COUNT()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_row-count) | The number of rows affected |
 | [`SCHEMA()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_schema) | Synonym for `DATABASE()`  |
 | [`SESSION_USER()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_session-user) | Synonym for `USER()`    |
 | [`SYSTEM_USER()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_system-user) | Synonym for `USER()`   |
 | [`USER()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_user) | Return the user name and host name provided by the client    |
 | [`VERSION()`](https://dev.mysql.com/doc/refman/5.7/en/information-functions.html#function_version) | Return a string that indicates the MySQL server version   |
 | `TIDB_VERSION()` | Return a string that indicates the TiDB server version |
+
+## Unsupported functions
+
+* `CHARSET()`
+* `COERCIBILITY()`
+* `COLLATION()`
diff --git a/dev/reference/sql/functions-and-operators/miscellaneous-functions.md b/dev/reference/sql/functions-and-operators/miscellaneous-functions.md
@@ -6,12 +6,14 @@ category: reference
 
 # Miscellaneous Functions
 
+TiDB supports most of the [miscellaneous functions](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html) available in MySQL 5.7.
+
+## Supported functions
+
 | Name | Description  |
 |:------------|:-----------------------------------------------------------------------------------------------|
-| [`ANY_VALUE()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_any-value)              | Suppress ONLY_FULL_GROUP_BY value rejection       |
-| [`SLEEP()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_sleep)                      | Sleep for a number of seconds                     |
-| [`UUID()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_uuid)                        | Return a Universal Unique Identifier (UUID)       |
-| [`VALUES()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values)                    | Defines the values to be used during an INSERT    |
+| [`ANY_VALUE()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_any-value)              | Suppress `ONLY_FULL_GROUP_BY` value rejection       |
+| [`DEFAULT()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_default)                  | Returns the default value for a table column      |
 | [`INET_ATON()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_inet-aton)              | Return the numeric value of an IP address         |
 | [`INET_NTOA()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_inet-ntoa)              | Return the IP address from a numeric value        |
 | [`INET6_ATON()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_inet6-aton)            | Return the numeric value of an IPv6 address       |
@@ -20,5 +22,17 @@ category: reference
 | [`IS_IPV4_COMPAT()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_is-ipv4-compat)    | Whether argument is an IPv4-compatible address    |
 | [`IS_IPV4_MAPPED()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_is-ipv4-mapped)    | Whether argument is an IPv4-mapped address        |
 | [`IS_IPV6()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_is-ipv6)                  | Whether argument is an IPv6 address               |
-| [`GET_LOCK()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock)                | Get a named lock                                  |
-| [`RELEASE_LOCK()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_release-lock)        | Releases the named lock                           |
+| [`NAME_CONST()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_name-const)            | Can be used to rename a column name               |
+| [`SLEEP()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_sleep)                      | Sleep for a number of seconds                     |
+| [`UUID()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_uuid)                        | Return a Universal Unique Identifier (UUID)       |
+| [`VALUES()`](https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_values)                    | Defines the values to be used during an INSERT    |
+
+## Unsupported functions
+
+| 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/10929) |
+| [`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/10929) |
+| [`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 |
+
diff --git a/dev/reference/sql/functions-and-operators/numeric-functions-and-operators.md b/dev/reference/sql/functions-and-operators/numeric-functions-and-operators.md
@@ -6,7 +6,7 @@ category: reference
 
 # Numeric Functions and Operators
 
-This document describes the arithmetic operators and mathematical functions.
+TiDB supports all of the [numeric functions and operators](https://dev.mysql.com/doc/refman/5.7/en/numeric-functions.html) available in MySQL 5.7.
 
 ## Arithmetic operators