vacuumdb — garbage-collect and analyze a PostgreSQL database
vacuumdb
[connection-option
...] [option
...] [ -t
| --table
table
[( column
[,...] )] ] ... [dbname
]
vacuumdb
[connection-option
...] [option
...] [ [ -n
| --schema
schema
] | [ -N
| --exclude-schema
schema
] ] ... [dbname
]
vacuumdb
[connection-option
...] [option
...] -a
| --all
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:
-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 25.1.5.1).
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 25.1.5).
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.
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.
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 34.15).
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 34.16 for more information.
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
If you see anything in the documentation that is not correct, does not match your experience with the particular feature or requires further clarification, please use this form to report a documentation issue.