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MySQL Information Schema  /  The INFORMATION_SCHEMA SCHEMATA_EXTENSIONS Table

Chapter 30 The INFORMATION_SCHEMA SCHEMATA_EXTENSIONS Table

The SCHEMATA_EXTENSIONS table (available as of MySQL 8.0.22) augments the SCHEMATA table with information about schema options.

The SCHEMATA_EXTENSIONS table has these columns:

  • CATALOG_NAME

    The name of the catalog to which the schema belongs. This value is always def.

  • SCHEMA_NAME

    The name of the schema.

  • OPTIONS

    The options for the schema. If the schema is read only, the value contains READ ONLY=1. If the schema is not read only, no READ ONLY option appears.

Example

mysql> ALTER SCHEMA mydb READ ONLY = 1;
mysql> SELECT * FROM INFORMATION_SCHEMA.SCHEMATA_EXTENSIONS
       WHERE SCHEMA_NAME = 'mydb';
+--------------+-------------+-------------+
| CATALOG_NAME | SCHEMA_NAME | OPTIONS     |
+--------------+-------------+-------------+
| def          | mydb        | READ ONLY=1 |
+--------------+-------------+-------------+
mysql> ALTER SCHEMA mydb READ ONLY = 0;
mysql> SELECT * FROM INFORMATION_SCHEMA.SCHEMATA_EXTENSIONS
       WHERE SCHEMA_NAME = 'mydb';
+--------------+-------------+---------+
| CATALOG_NAME | SCHEMA_NAME | OPTIONS |
+--------------+-------------+---------+
| def          | mydb        |         |
+--------------+-------------+---------+

Notes