## 52.15. `pg_database`

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 The catalog `pg_database` stores information about the available databases. Databases are created with the [`CREATE DATABASE`](sql-createdatabase.html) command. Consult [Chapter 23](managing-databases.html) 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 52.15. `pg_database` Columns**

|                                                                                                                                                                                 Column Type<br/><br/> Description                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
|                                                                                                                                                                               `oid` `oid`<br/><br/> Row identifier                                                                                                                                                                               |
|                                                                                                                                                                             `datname` `name`<br/><br/> Database name                                                                                                                                                                             |
|                                                                                                                             `datdba` `oid` (references [`pg_authid`](catalog-pg-authid.html).`oid`)<br/><br/> Owner of the database, usually the user who created it                                                                                                                             |
|                                                                                                                            `encoding` `int4`<br/><br/> Character encoding for this database (`pg_encoding_to_char()` can translate this number to the encoding name)                                                                                                                             |
|                                                                                                                                                                   `datcollate` `name`<br/><br/> LC\_COLLATE for this database                                                                                                                                                                    |
|                                                                                                                                                                     `datctype` `name`<br/><br/> LC\_CTYPE for this database                                                                                                                                                                      |
|                                                                                                   `datistemplate` `bool`<br/><br/> 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`<br/><br/> If false then no one can connect to this database. This is used to protect the `template0` database from being altered.                                                                                                                      |
|                                                                                                                               `datconnlimit` `int4`<br/><br/> Sets maximum number of concurrent connections that can be made to this database. -1 means no limit.                                                                                                                                |
|                                                                                                                                                 `datlastsysoid` `oid`<br/><br/> Last system OID in the database; useful particularly to pg\_dump                                                                                                                                                 |
|`datfrozenxid` `xid`<br/><br/> 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`](catalog-pg-class.html).`relfrozenxid` values.|
|            `datminmxid` `xid`<br/><br/> 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`](catalog-pg-class.html).`relminmxid` values.            |
|                       `dattablespace` `oid` (references [`pg_tablespace`](catalog-pg-tablespace.html).`oid`)<br/><br/> The default tablespace for the database. Within this database, all tables for which [`pg_class`](catalog-pg-class.html).`reltablespace` is zero will be stored in this tablespace; in particular, all the non-shared system catalogs will be there.                       |
|                                                                                                                                                  `datacl` `aclitem[]`<br/><br/> Access privileges; see [Section 5.7](ddl-priv.html) for details                                                                                                                                                  |

