28.3.32 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

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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

• SCHEMATA_EXTENSIONS is a nonstandard INFORMATION_SCHEMA table.