A database catalog of a
database
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases ...
instance consists of
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the descriptive ...
in which definitions of database objects such as base tables, views (virtual tables),
synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are al ...
s, value ranges,
indexes,
users
Ancient Egyptian roles
* User (ancient Egyptian official), an ancient Egyptian nomarch (governor) of the Eighth Dynasty
* Useramen, an ancient Egyptian vizier also called "User"
Other uses
* User (computing), a person (or software) using an ...
, and user groups are stored.
The
SQL standard specifies a uniform means to access the catalog, called the
INFORMATION_SCHEMA, but not all
databases
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spa ...
follow this, even if they implement other aspects of the SQL standard. For an example of database-specific
metadata
Metadata is "data that provides information about other data", but not the content of the data, such as the text of a message or the image itself. There are many distinct types of metadata, including:
* Descriptive metadata – the descriptive ...
access methods, see
Oracle metadata.
See also
*
Data dictionary
A data dictionary, or metadata repository, as defined in the ''IBM Dictionary of Computing'', is a "centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format". ''Oracle'' defines it ...
References
Database theory
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