vacuumdb — garbage-collect and analyze a PostgreSQL database
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vacuumdb is a utility for cleaning a PostgreSQL database. vacuumdb will also generate internal statistics used by the PostgreSQL query optimizer.
vacuumdb is a wrapper around the SQL command VACUUM. There is no effective difference between vacuuming and analyzing databases via this utility and via other methods for accessing the server.
vacuumdb accepts the following command-line arguments:
Vacuum all databases.
Specifies the name of the database to be cleaned or analyzed, when
--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.
Echo the commands that vacuumdb generates and sends to the server.
Perform “full” vacuuming.
Aggressively “freeze” tuples.
Execute the vacuum or analyze commands in parallel by running
njobs commands simultaneously. This option reduces the time of the processing but it also increases the load on the database server.
vacuumdb will open
njobs connections to the database, so make sure your max_connections setting is high enough to accommodate all connections.
Note that using this mode together with the
FULL) option might cause deadlock failures if certain system catalogs are processed in parallel.
Do not display progress messages.
Clean or analyze
table only. Column names can be specified only in conjunction with the
--analyze-only options. Multiple tables can be vacuumed by writing multiple
If you specify columns, you probably have to escape the parentheses from the shell. (See examples below.)
Print detailed information during processing.
Print the vacuumdb version and exit.
Also calculate statistics for use by the optimizer.
Only calculate statistics for use by the optimizer (no vacuum).
Only calculate statistics for use by the optimizer (no vacuum), like
--analyze-only. Run several (currently three) stages of analyze with different configuration settings, to produce usable statistics faster.
This option is useful to analyze a database that was newly populated from a restored dump or by
pg_upgrade. This option will try to create some statistics as fast as possible, to make the database usable, and then produce full statistics in the subsequent stages.
Show help about vacuumdb command line arguments, and exit.
vacuumdb also accepts the following command-line arguments for connection parameters:
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.
Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.
User name to connect as.
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.
Force vacuumdb to prompt for a password before connecting to a database.
This option is never essential, since vacuumdb will automatically prompt for a password if the server demands password authentication. However, vacuumdb 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.
Specifies the name of the database to connect to to discover which databases should be vacuumed, when
--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.
Default connection parameters
This utility, like most other PostgreSQL utilities, also uses the environment variables supported by libpq (see Section 33.14).
In case of difficulty, see VACUUM 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.
vacuumdb might need to connect several times to the PostgreSQL server, asking for a password each time. It is convenient to have a
~/.pgpass file in such cases. See Section 33.15 for more information.
To clean the database
To clean and analyze for the optimizer a database named
vacuumdb --analyze bigdb
To clean a single table
foo in a database named
xyzzy, and analyze a single column
bar of the table for the optimizer:
vacuumdb --analyze --verbose --table='foo(bar)' xyzzy