clusterdb

clusterdb

1

Application

clusterdb

cluster a

PostgreSQL

database

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 [???](#sql-cluster). 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](#libpq-connstring). 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](#libpq-connstring). 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

PG\_COLOR

:   Specifies whether to use color in diagnostic messages. Possible
    values are `always`, `auto` and `never`.

This utility, like most other PostgreSQL utilities, also uses the
environment variables supported by libpq (see [???](#libpq-envars)).

Diagnostics
===========

In case of difficulty, see [???](#sql-cluster) and [???](#app-psql) 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
========
