## 52.15. `pg_database`
[]()
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
Description |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| `oid` `oid`
Row identifier |
| `datname` `name`
Database name |
| `datdba` `oid` (references [`pg_authid`](catalog-pg-authid.html).`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`](catalog-pg-class.html).`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`](catalog-pg-class.html).`relminmxid` values. |
| `dattablespace` `oid` (references [`pg_tablespace`](catalog-pg-tablespace.html).`oid`)
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[]`
Access privileges; see [Section 5.7](ddl-priv.html) for details |