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.
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.
If this is not specified and -a (or
--all) is not used, the database name is read
from the environment variable PGDATABASE. If
that is not set, the user name specified for the connection is
used.
-e --echo
Echo the commands that clusterdb generates
and sends to the server.
-q --quiet
Do not display a response.
-t table --table table
Cluster table only.
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 --password
Force password prompt.
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 29.12).
Diagnostics
In case of difficulty, see CLUSTER and 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: