vacuumdb

vacuumdb

1

Application

vacuumdb

garbage-collect and analyze a

PostgreSQL

database

vacuumdb

connection-option

option

-t

\--table

table

(

column

\[,\...\] )

dbname

vacuumdb

connection-option

option

-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`](#sql-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.

`-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](#libpq-connstring). 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.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 9.6
    > and later.

`-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.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 12
    > and later.

`-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 [???](#guc-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 [???](#vacuum-for-multixact-wraparound)).

    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.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 9.6
    > and later.

`--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 [???](#vacuum-for-wraparound)).

    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.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 9.6
    > and later.

`--no-index-cleanup`

:   Do not remove index entries pointing to dead tuples.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 12
    > and later.

`--no-process-toast`

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

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 14
    > and later.

`--no-truncate`

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

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 12
    > and later.

`-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
    [???](#sql-vacuum).

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 13
    > and later.

`-q`; `--quiet`

:   Do not display progress messages.

`--skip-locked`

:   Skip relations that cannot be immediately locked for processing.

    > **Note**
    >
    > This option is only available for servers running PostgreSQL 12
    > and later.

`-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
    [???](#guc-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](#libpq-connstring). 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 [???](#libpq-envars)).

Diagnostics
===========

In case of difficulty, see [???](#sql-vacuum) and [???](#app-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.

Notes
=====

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 [???](#libpq-pgpass) for more information.

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

See Also
========
