Information Schema TABLES Table
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The Information Schema table shows information about the various non-TEMPORARY
tables and views on the server.
It contains the following columns:
Column | Description |
---|---|
TABLE_CATALOG | Always def . |
TABLE_SCHEMA | Database name. |
TABLE_NAME | Table name. |
TABLE_TYPE | One of BASE TABLE for a regular table, VIEW for a view, LOCAL TEMPORARY , GLOBAL TEMPORARY . |
ENGINE | Storage Engine. |
VERSION | Version number from the table's .frm file |
ROW_FORMAT | Row format. |
TABLE_ROWS | Number of rows in the table. Some engines, such as XtraDB and InnoDB may store an estimate. |
AVG_ROW_LENGTH | Average row length in the table. |
DATA_LENGTH | Length of the data. |
MAX_DATA_LENGTH | Maximum length of the data file, ie the total number of bytes that could be stored in the table. |
INDEX_LENGTH | Length of the index file. |
DATA_FREE | Bytes allocated by unused. For InnoDB tables in a shared tablespace, the free space of the shared tablespace with small safety margin. An estimate in the case of partitioned tables - see the PARTITIONS table. |
AUTO_INCREMENT | Next AUTO_INCREMENT value. |
CREATE_TIME | Time the table was created. |
UPDATE_TIME | Time the table was last updated. On Windows, the timestamp is not updated on update, so MyISAM values will be inaccurate. In InnoDB, if shared tablespaces are used, will be NULL, while buffering can also delay the update, so the value will differ from the actual time of the last UPDATE, INSERT or DELETE. |
CHECK_TIME | Time the table was last checked. Not kept by all storage engines, in which case will be NULL. |
TABLE_COLLATION | Character set and collation. |
CHECKSUM | Live checksum value, if any. |
CREATE_OPTIONS | Extra CREATE TABLE options. |
TABLE_COMMENT | Table comment provided when MariaDB created the table. |
Although the table is standard in the Information Schema, all but TABLE_CATALOG, TABLE_SCHEMA, TABLE_NAME, TABLE_TYPE, ENGINE and VERSION are MySQL and MariaDB extensions.
Example
SELECT * FROM INFORMATION_SCHEMA.TABLES\G ... *************************** 175. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: test TABLE_NAME: xx4 TABLE_TYPE: BASE TABLE ENGINE: MyISAM VERSION: 10 ROW_FORMAT: Fixed TABLE_ROWS: 0 AVG_ROW_LENGTH: 0 DATA_LENGTH: 0 MAX_DATA_LENGTH: 1970324836974591 INDEX_LENGTH: 1024 DATA_FREE: 0 AUTO_INCREMENT: NULL CREATE_TIME: 2013-10-31 14:45:35 UPDATE_TIME: 2013-10-31 14:45:35 CHECK_TIME: NULL TABLE_COLLATION: latin1_swedish_ci CHECKSUM: NULL CREATE_OPTIONS: key_block_size=46 TABLE_COMMENT: *************************** 176. row *************************** TABLE_CATALOG: def TABLE_SCHEMA: test TABLE_NAME: xx5 TABLE_TYPE: BASE TABLE ENGINE: InnoDB VERSION: 10 ROW_FORMAT: Compact TABLE_ROWS: 0 AVG_ROW_LENGTH: 0 DATA_LENGTH: 16384 MAX_DATA_LENGTH: 0 INDEX_LENGTH: 0 DATA_FREE: 0 AUTO_INCREMENT: NULL CREATE_TIME: 2013-11-11 09:54:11 UPDATE_TIME: NULL CHECK_TIME: NULL TABLE_COLLATION: latin1_swedish_ci CHECKSUM: NULL CREATE_OPTIONS: key_block_size=46 TABLE_COMMENT: ...
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