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pg_database

The catalog pg_database stores information about the available databases. Databases are created with the CREATE DATABASE command. Consult Chapter 10 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.

pg_database Columns

Column Type	Description
`oid` `oid`	Row identifier
`datname` `name`	Database name
`datdba` `oid` (references pg_authid.`oid`)	Owner of the database, usually the user who created it
`encoding` `int4`	Character encoding for this database (`pg_encoding_to_char()` can translate this number to the encoding name)
`datcollate` `name`	LC_COLLATE for this database
`datctype` `name`	LC_CTYPE for this database
`datistemplate` `bool`	If true, then this database can be cloned by any user with `CREATEDB` privileges; if false, then only superusers or the owner of the database can clone it.
`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_xact` to be shrunk. It is the minimum of the per-table pg_class.`relfrozenxid` values.
`datminmxid` `xid`	All multixact 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 multixact ID wraparound or to allow `pg_multixact` to be shrunk. It is the minimum of the per-table pg_class.`relminmxid` values.
`dattablespace` `oid` (references 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;