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| title: pg_database |
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| The `pg_database` system catalog table stores information about the available databases. Databases are created with the `CREATE DATABASE` SQL command. Unlike most system catalogs, `pg_database` is shared across all databases in the system. There is only one copy of `pg_database` per system, not one per database. |
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| <a id="topic1__gj143898"></a> |
| <span class="tablecap">Table 1. pg\_catalog.pg\_database</span> |
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| | column | type | references | description | |
| |-----------------|-------------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| |
| | `datname` | name | | Database name. | |
| | `datdba` | oid | pg\_authid.oid | Owner of the database, usually the user who created it. | |
| | `encoding` | integer | | Character encoding for this database. `pg_encoding_to_char()` can translate this number to the encoding name. | |
| | `datistemplate` | boolean | | 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` | boolean | | If false then no one can connect to this database. This is used to protect the `template0` database from being altered. | |
| | `datconnlimit` | integer | | Sets the maximum number of concurrent connections that can be made to this database. `-1` means no limit. | |
| | `datlastsysoid` | oid | | Last system OID in the database. | |
| | `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. | |
| | `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. All non-shared system catalogs will also be there. | |
| | `datconfig` | text\[\] | | Session defaults for user-settable server configuration parameters. | |
| | `datacl` | aclitem\[\] | | Database access privileges as given by `GRANT` and `REVOKE`. | |
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