The catalog pg_database stores information about the available databases. Databases are created with the CREATE DATABASE command. Consult Chapter 21 for details about the meaning of some of the parameters.
Unlike most system catalogs, pg_database is shared across all databases of a cluster: there is only one copy of pg_database per cluster, not one per database.
Table 47-15. pg_database Columns
|oid||oid||Row identifier (hidden attribute; must be explicitly selected)|
|datdba||oid||pg_authid.oid||Owner of the database, usually the user who created it|
|encoding||int4||Character encoding for this database (
|datcollate||name||LC_COLLATE for this database|
|datctype||name||LC_CTYPE for this database|
|datistemplate||bool||If true then this database can be used in the TEMPLATE clause of CREATE DATABASE to create a new database as a clone of this one|
|datallowconn||bool||If false then no one can connect to this database. This is used to protect the template0 database from being altered.|
|datconnlimit||int4||Sets maximum number of concurrent connections that can be made to this database. -1 means no limit.|
|datlastsysoid||oid||Last system OID in the database; useful particularly to pg_dump|
|datfrozenxid||xid||All transaction IDs before this one have been replaced with a permanent ("frozen") transaction ID in this database. This is used to track whether the database needs to be vacuumed in order to prevent transaction ID wraparound or to allow pg_clog to be shrunk. It is the minimum of the per-table pg_class.relfrozenxid values.|
|datminmxid||xid||All multitransaction IDs before this one have been replaced with a transaction ID in this database. This is used to track whether the database needs to be vacuumed in order to prevent transaction ID wraparound or to allow pg_clog to be shrunk. It is the minimum of the per-table pg_class.relminmxid values.|
|dattablespace||oid||pg_tablespace.oid||The default tablespace for the database. Within this database, all tables for which pg_class.reltablespace is zero will be stored in this tablespace; in particular, all the non-shared system catalogs will be there.|
|datacl||aclitem||Access privileges; see GRANT and REVOKE for details|
Please use this form to add your own comments regarding your experience with particular features of PostgreSQL, clarifications of the documentation, or hints for other users. Please note, this is not a support forum, and your IP address will be logged. If you have a question or need help, please see the faq, try a mailing list, or join us on IRC. Note that submissions containing URLs or other keywords commonly found in 'spam' comments may be silently discarded. Please contact the webmaster if you think this is happening to you in error.
Proceed to the comment form.