Database catalog

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A database catalog of a database instance consists of metadata in which definitions of database objects such as base tables, views (virtual tables), synonyms, value ranges, indexes, users, and user groups are stored. [1] [2]

The SQL standard specifies a uniform means to access the catalog, called the INFORMATION_SCHEMA, but not all databases follow this, even if they implement other aspects of the SQL standard. For an example of database-specific metadata access methods, see Oracle metadata.

See also

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 => SELECT count(table_name) FROM information_schema.tables;  count   -------  99    => SELECT column_name, data_type, column_default, is_nullable  FROM information_schema.columns WHERE table_name='alpha';  column_name | data_type | column_default | is_nullable   -------------+-----------+----------------+-------------  foo | integer | | YES  bar | character | | YES    => SELECT * FROM information_schema.information_schema_catalog_name;  catalog_name   --------------  johnd  

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References

  1. Paul C. Tinnirello (1999). Systems Development Handbook . CRC Press. ISBN   0-8493-9822-3.
  2. CREATE VIEW (Transact-SQL) in SQL Server 2008 Books Online, Microsoft Corporation