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vacuumdb

vacuumdb
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vacuumdb

vacuumdb - garbage-collect and analyze a PostgreSQL database

Synopsis

vacuumdb [ connection-option ...] [ option ...] [ -t | --table table [( column [,...] )] ] ... [ dbname | -a | --all ]

vacuumdb [ connection-option ...] [ option ...] [ -n | --schema schema ] ... [ dbname | -a | --all ]

vacuumdb [ connection-option ...] [ option ...] [ -N | --exclude-schema schema ] ... [ dbname | -a | --all ]

Description

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.

Options

vacuumdb accepts the following command-line arguments:

-a --all

Vacuum all databases.

--buffer-usage-limit size

Specifies the Buffer Access Strategy ring buffer size for a given invocation of vacuumdb . This size is used to calculate the number of shared buffers which will be reused as part of this strategy. See VACUUM .

[ -d ] dbname [ --dbname= ] dbname

Specifies the name of the database to be cleaned or analyzed, 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.

--disable-page-skipping

Disable skipping pages based on the contents of the visibility map.

-e --echo

Echo the commands that vacuumdb generates and sends to the server.

-f --full

Perform " full " vacuuming.

-F --freeze

Aggressively " freeze " tuples.

--force-index-cleanup

Always remove index entries pointing to dead tuples.

-j njobs --jobs= njobs

Execute the vacuum or analyze commands in parallel by running njobs commands simultaneously. This option may reduce the processing time 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 -f ( FULL ) option might cause deadlock failures if certain system catalogs are processed in parallel.

--min-mxid-age mxid_age

Only execute the vacuum or analyze commands on tables with a multixact ID age of at least mxid_age . This setting is useful for prioritizing tables to process to prevent multixact ID wraparound (see Section 24.1.5.1 ).

For the purposes of this option, the multixact ID age of a relation is the greatest of the ages of the main relation and its associated TOAST table, if one exists. Since the commands issued by vacuumdb will also process the TOAST table for the relation if necessary, it does not need to be considered separately.

--min-xid-age xid_age

Only execute the vacuum or analyze commands on tables with a transaction ID age of at least xid_age . This setting is useful for prioritizing tables to process to prevent transaction ID wraparound (see Section 24.1.5 ).

For the purposes of this option, the transaction ID age of a relation is the greatest of the ages of the main relation and its associated TOAST table, if one exists. Since the commands issued by vacuumdb will also process the TOAST table for the relation if necessary, it does not need to be considered separately.

-n schema --schema= schema

Clean or analyze all tables in schema only. Multiple schemas can be vacuumed by writing multiple -n switches.

-N schema --exclude-schema= schema

Do not clean or analyze any tables in schema . Multiple schemas can be excluded by writing multiple -N switches.

--no-index-cleanup

Do not remove index entries pointing to dead tuples.

--no-process-main

Skip the main relation.

--no-process-toast

Skip the TOAST table associated with the table to vacuum, if any.

--no-truncate

Do not truncate empty pages at the end of the table.

-P parallel_workers --parallel= parallel_workers

Specify the number of parallel workers for parallel vacuum . This allows the vacuum to leverage multiple CPUs to process indexes. See VACUUM .

-q --quiet

Do not display progress messages.

--skip-locked

Skip relations that cannot be immediately locked for processing.

-t table [ ( column [,...]) ] --table= table [ ( column [,...]) ]

Clean or analyze table only. Column names can be specified only in conjunction with the --analyze or --analyze-only options. Multiple tables can be vacuumed by writing multiple -t switches.

Tip

If you specify columns, you probably have to escape the parentheses from the shell. (See examples below.)

-v --verbose

Print detailed information during processing.

-V --version

Print the vacuumdb version and exit.

-z --analyze

Also calculate statistics for use by the optimizer.

-Z --analyze-only

Only calculate statistics for use by the optimizer (no vacuum).

--analyze-in-stages

Only calculate statistics for use by the optimizer (no vacuum), like --analyze-only . Run three stages of analyze; the first stage uses the lowest possible statistics target (see default_statistics_target ) to produce usable statistics faster, and subsequent stages build the full statistics.

This option is only useful to analyze a database that currently has no statistics or has wholly incorrect ones, such as if it is newly populated from a restored dump or by pg_upgrade . Be aware that running with this option in a database with existing statistics may cause the query optimizer choices to become transiently worse due to the low statistics targets of the early stages.

-? --help

Show help about vacuumdb command line arguments, and exit.

vacuumdb 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 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.

--maintenance-db= dbname

Specifies the name of the database to connect to to discover which databases should be vacuumed, 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
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 Section 32.15 ).

Diagnostics

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.

Examples

To clean the database test :

$ vacuumdb test

To clean and analyze for the optimizer a database named bigdb :

$ 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

To clean all tables in the foo and bar schemas in a database named xyzzy :

$ vacuumdb --schema='foo' --schema='bar' xyzzy

vacuumdb

vacuumdb

Synopsis

Description

Options

Tip

Environment

Diagnostics

Examples

See Also