vacuumdb — garbage-collect and analyze a PostgreSQL database
column [,...] )] ] ... [
option...] [ [
schema ] | [
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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:
Vacuum all databases.
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.
Specifies the name of the database to be cleaned or analyzed, when
--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 skipping pages based on the contents of the visibility map.
Echo the commands that vacuumdb generates and sends to the server.
Perform “full” vacuuming.
Aggressively “freeze” tuples.
Always remove index entries pointing to dead tuples.
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
FULL) option might cause deadlock failures if certain system catalogs are processed in parallel.
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 220.127.116.11).
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.
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.
Clean or analyze all tables in
schema only. Multiple schemas can be vacuumed by writing multiple
Do not clean or analyze any tables in
schema. Multiple schemas can be excluded by writing multiple
Do not remove index entries pointing to dead tuples.
Skip the main relation.
Skip the TOAST table associated with the table to vacuum, if any.
Do not truncate empty pages at the end of the table.
Specify the number of parallel workers for parallel vacuum. This allows the vacuum to leverage multiple CPUs to process indexes. See VACUUM.
Do not display progress messages.
Skip relations that cannot be immediately locked for processing.
Clean or analyze
table only. Column names can be specified only in conjunction with the
--analyze-only options. Multiple tables can be vacuumed by writing multiple
If you specify columns, you probably have to escape the parentheses from the shell. (See examples below.)
Print detailed information during processing.
Print the vacuumdb version and exit.
Also calculate statistics for use by the optimizer.
Only calculate statistics for use by the optimizer (no vacuum).
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.
Show help about vacuumdb command line arguments, and exit.
vacuumdb also accepts the following command-line arguments for connection parameters:
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.
Specifies the TCP port or local Unix domain socket file extension on which the server is listening for connections.
User name to connect as.
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.
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.
Specifies the name of the database to connect to to discover which databases should be vacuumed, when
--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.
Default connection parameters
Specifies whether to use color in diagnostic messages. Possible values are
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
To clean and analyze for the optimizer a database named
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
bar schemas in a database named
vacuumdb --schema='foo' --schema='bar' xyzzy