NAME

       clusterdb - cluster a PostgreSQL database

SYNOPSIS

       clusterdb [connection-option...] [--verbose | -v] [ --table | -t table ]...  [dbname]

       clusterdb [connection-option...] [--verbose | -v] --all | -a

DESCRIPTION

       clusterdb is a utility for reclustering tables in a PostgreSQL database. It finds tables
       that have previously been clustered, and clusters them again on the same index that was
       last used. Tables that have never been clustered are not affected.

       clusterdb is a wrapper around the SQL command CLUSTER(7). There is no effective difference
       between clustering databases via this utility and via other methods for accessing the
       server.

OPTIONS

       clusterdb accepts the following command-line arguments:

       -a
       --all
           Cluster all databases.

       [-d] dbname
       [--dbname=]dbname
           Specifies the name of the database to be clustered, when -a/--all is not used. If this
           is not specified, the database name is read from the environment variable PGDATABASE.
           If that is not set, the user name specified for the connection is used. The dbname can
           be a connection string. If so, connection string parameters will override any
           conflicting command line options.

       -e
       --echo
           Echo the commands that clusterdb generates and sends to the server.

       -q
       --quiet
           Do not display progress messages.

       -t table
       --table=table
           Cluster table only. Multiple tables can be clustered by writing multiple -t switches.

       -v
       --verbose
           Print detailed information during processing.

       -V
       --version
           Print the clusterdb version and exit.

       -?
       --help
           Show help about clusterdb command line arguments, and exit.

       clusterdb also accepts the following command-line arguments for connection parameters:

       -h host
       --host=host
           Specifies the host name of the machine on which the server is running. If the value
           begins with a slash, it is used as the directory for the Unix domain socket.

       -p port
       --port=port
           Specifies the TCP port or local Unix domain socket file extension on which the server
           is listening for connections.

       -U username
       --username=username
           User name to connect as.

       -w
       --no-password
           Never issue a password prompt. If the server requires password authentication and a
           password is not available by other means such as a .pgpass file, the connection
           attempt will fail. This option can be useful in batch jobs and scripts where no user
           is present to enter a password.

       -W
       --password
           Force clusterdb to prompt for a password before connecting to a database.

           This option is never essential, since clusterdb will automatically prompt for a
           password if the server demands password authentication. However, clusterdb will waste
           a connection attempt finding out that the server wants a password. In some cases it is
           worth typing -W to avoid the extra connection attempt.

       --maintenance-db=dbname
           Specifies the name of the database to connect to to discover which databases should be
           clustered, when -a/--all is used. If not specified, the postgres database will be
           used, or if that does not exist, template1 will be used. This can be a connection
           string. If so, connection string parameters will override any conflicting command line
           options. Also, connection string parameters other than the database name itself will
           be re-used when connecting to other databases.

ENVIRONMENT

       PGDATABASE
       PGHOST
       PGPORT
       PGUSER
           Default connection parameters

       This utility, like most other PostgreSQL utilities, also uses the environment variables
       supported by libpq (see Section 33.14).

DIAGNOSTICS

       In case of difficulty, see CLUSTER(7) and psql(1) for discussions of potential problems
       and error messages. The database server must be running at the targeted host. Also, any
       default connection settings and environment variables used by the libpq front-end library
       will apply.

EXAMPLES

       To cluster the database test:

           $ clusterdb test

       To cluster a single table foo in a database named xyzzy:

           $ clusterdb --table=foo xyzzy

SEE ALSO

       CLUSTER(7)