vacuumdb
vacuumdb — garbage-collect and analyze a Postgres Pro database
Synopsis
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
Description
vacuumdb is a utility for cleaning a Postgres Pro database. vacuumdb will also generate internal statistics used by the Postgres Pro 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--allVacuum all databases.
--buffer-usage-limitsizeSpecifies 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=]dbnameSpecifies the name of the database to be cleaned or analyzed, when
-a/--allis 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. Thedbnamecan be a connection string. If so, connection string parameters will override any conflicting command line options.--disable-page-skippingDisable skipping pages based on the contents of the visibility map.
-e--echoEcho the commands that vacuumdb generates and sends to the server.
-f--fullPerform “full” vacuuming.
-F--freezeAggressively “freeze” tuples.
--force-index-cleanupAlways remove index entries pointing to dead tuples.
-jnjobs--jobs=njobsExecute the vacuum or analyze commands in parallel by running
njobscommands simultaneously. This option may reduce the processing time but it also increases the load on the database server.vacuumdb will open
njobsconnections 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-agemxid_ageOnly 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 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 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-agexid_ageOnly 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 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 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.
-nschema--schema=schemaClean or analyze all tables in
schemaonly. Multiple schemas can be vacuumed by writing multiple-nswitches.-Nschema--exclude-schema=schemaDo not clean or analyze any tables in
schema. Multiple schemas can be excluded by writing multiple-Nswitches.--no-index-cleanupDo not remove index entries pointing to dead tuples.
--no-process-mainSkip the main relation.
--no-process-toastSkip the TOAST table associated with the table to vacuum, if any.
--no-truncateDo not truncate empty pages at the end of the table.
-Pparallel_workers--parallel=parallel_workersSpecify the number of parallel workers for parallel vacuum. This allows the vacuum to leverage multiple CPUs to process indexes. See VACUUM.
-q--quietDo not display progress messages.
--skip-lockedSkip relations that cannot be immediately locked for processing.
-ttable[ (column[,...]) ]--table=table[ (column[,...]) ]Clean or analyze
tableonly. Column names can be specified only in conjunction with the--analyzeor--analyze-onlyoptions. Multiple tables can be vacuumed by writing multiple-tswitches.Tip
If you specify columns, you probably have to escape the parentheses from the shell. (See examples below.)
-v--verbosePrint detailed information during processing.
-V--versionPrint the vacuumdb version and exit.
-z--analyzeAlso calculate statistics for use by the optimizer.
-Z--analyze-onlyOnly calculate statistics for use by the optimizer (no vacuum).
--analyze-in-stagesOnly 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.-?--helpShow help about vacuumdb command line arguments, and exit.
vacuumdb also accepts the following command-line arguments for connection parameters:
-hhost--host=hostSpecifies 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=portSpecifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.
-Uusername--username=usernameUser name to connect as.
-w--no-passwordNever issue a password prompt. If the server requires password authentication and a password is not available by other means such as a
.pgpassfile, 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--passwordForce 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
-Wto avoid the extra connection attempt.--maintenance-db=dbnameWhen the
-a/--allis used, connect to this database to gather the list of databases to vacuum. If not specified, thepostgresdatabase will be used, or if that does not exist,template1will 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
PGDATABASEPGHOSTPGPORTPGUSERDefault connection parameters
PG_COLORSpecifies whether to use color in diagnostic messages. Possible values are
always,autoandnever.
This utility, like most other Postgres Pro utilities, also uses the environment variables supported by libpq (see Section 33.15).
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.
Notes
vacuumdb might need to connect several times to the Postgres Pro server, asking for a password each time. It is convenient to have a ~/.pgpass file in such cases. See Section 33.16 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
To clean all tables in the foo and bar schemas in a database named xyzzy:
$vacuumdb --schema='foo' --schema='bar' xyzzy