vacuumdb
vacuumdb — garbage-collect and analyze aPostgres Pro 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 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-limit
size
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
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 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-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 (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-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 (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.
-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 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.
-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 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 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 aboutvacuumdb 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
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 are
always
,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