The catalog pg_database
stores information
about the available databases. Databases are created with the
CREATE DATABASE
command. Consult
Chapter 19, Managing Databases 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 42.15. pg_database
Columns
Name | Type | References | Description |
---|---|---|---|
datname |
name |
Database name | |
datdba |
oid |
|
Owner of the database, usually the user who created it |
encoding |
int4 |
Character encoding 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 | |
datvacuumxid |
xid |
All rows inserted or deleted by transaction IDs before this one have been marked as known committed or known aborted in this database. This is used to determine when commit-log space can be recycled. | |
datfrozenxid |
xid |
All rows inserted by transaction IDs before this one have been relabeled with a permanent (“frozen”) transaction ID in this database. This is useful to check whether a database must be vacuumed soon to avoid transaction ID wrap-around problems. | |
dattablespace |
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.
|
datconfig |
text[] |
Session defaults for run-time configuration variables | |
datacl |
aclitem[] |
Access privileges; see GRANT and REVOKE for details. |