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
touched.
clusterdb is a shell script wrapper around the
backend command
CLUSTER via
the PostgreSQL interactive terminal
psql. There is no effective
difference between clustering databases via this or other methods.
psql must be found by the script and
a database server must be running at the targeted host. Also, any default
settings and environment variables available to psql
and the libpq front-end library do apply.
clusterdb might need to connect several
times to the PostgreSQL server, asking for
a password each time. It is convenient to have a
$HOME/.pgpass file in such cases.
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 Clusters 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 host begins with a slash, it is used
as the directory for the Unix domain socket.
- -p port
--port port Specifies the Internet TCP/IP 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.
Examples
To cluster the database test:
$ clusterdb test
To cluster a single table
foo in a database named
xyzzy:
$ clusterdb --table foo xyzzy
