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vacuumdb
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vacuumdb

vacuumdb — garbage-collect and analyze aPostgres Pro database

Synopsis

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

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

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

Description

vacuumdb is a utility for cleaning aPostgres Pro database.vacuumdb will also generate internal statistics used by thePostgres Pro query optimizer.

vacuumdb is a wrapper around the SQL commandVACUUM. 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-limitsize

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

[-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 variablePGDATABASE. If that is not set, the user name specified for the connection is used. Thedbname can be aconnection 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 thatvacuumdb generates and sends to the server.

-f
--full

Performfull vacuuming.

-F
--freeze

Aggressivelyfreeze tuples.

--force-index-cleanup

Always remove index entries pointing to dead tuples.

-jnjobs
--jobs=njobs

Execute the vacuum or analyze commands in parallel by runningnjobs commands simultaneously. This option may reduce the processing time but it also increases the load on the database server.

vacuumdb will opennjobs connections to the database, so make sure yourmax_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-agemxid_age

Only execute the vacuum or analyze commands on tables with a multixact ID age of at leastmxid_age. This setting is useful for prioritizing tables to process to prevent multixact ID wraparound (seeSection 23.1.5.1).

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 associatedTOAST table, if one exists. Since the commands issued byvacuumdb will also process theTOAST table for the relation if necessary, it does not need to be considered separately.

--min-xid-agexid_age

Only execute the vacuum or analyze commands on tables with a transaction ID age of at leastxid_age. This setting is useful for prioritizing tables to process to prevent transaction ID wraparound (seeSection 23.1.5).

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 associatedTOAST table, if one exists. Since the commands issued byvacuumdb will also process theTOAST table for the relation if necessary, it does not need to be considered separately.

-nschema
--schema=schema

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

-Nschema
--exclude-schema=schema

Do not clean or analyze any tables inschema. 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.

-Pparallel_workers
--parallel=parallel_workers

Specify the number of parallel workers forparallel vacuum. This allows the vacuum to leverage multiple CPUs to process indexes. SeeVACUUM.

-q
--quiet

Do not display progress messages.

--skip-locked

Skip relations that cannot be immediately locked for processing.

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

Clean or analyzetable 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 thevacuumdb 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 (seedefault_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 bypg_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 aboutvacuumdb command line arguments, and exit.

vacuumdb also accepts the following command-line arguments for connection parameters:

-hhost
--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.

-pport
--port=port

Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.

-Uusername
--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

Forcevacuumdb to prompt for a password before connecting to a database.

This option is never essential, sincevacuumdb 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

When the-a/--all is used, connect to this database to gather the list of databases to vacuum. If not specified, thepostgres database will be used, or if that does not exist,template1 will be used. This can be aconnection 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 arealways,auto andnever.

This utility, like most otherPostgres Pro utilities, also uses the environment variables supported bylibpq (seeSection 32.15).

Diagnostics

In case of difficulty, seeVACUUM andpsql 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 thelibpq front-end library will apply.

Examples

To clean the databasetest:

$vacuumdb test

To clean and analyze for the optimizer a database namedbigdb:

$vacuumdb --analyze bigdb

To clean a single tablefoo in a database namedxyzzy, and analyze a single columnbar of the table for the optimizer:

$vacuumdb --analyze --verbose --table='foo(bar)' xyzzy

To clean all tables in thefoo andbar schemas in a database namedxyzzy:

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

See Also

VACUUM

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