vacuumlo Man page

VACUUMLO(1) PostgreSQL 9.5.5 Documentation VACUUMLO(1)


vacuumlo – remove orphaned large objects from a PostgreSQL database


vacuumlo [option…] dbname…


vacuumlo is a simple utility program that will remove any “orphaned”
large objects from a PostgreSQL database. An orphaned large object (LO)
is considered to be any LO whose OID does not appear in any oid or lo
data column of the database.

If you use this, you may also be interested in the lo_manage trigger in
the lo module. lo_manage is useful to try to avoid creating orphaned
LOs in the first place.

All databases named on the command line are processed.


vacuumlo accepts the following command-line arguments:

-l limit
Remove no more than limit large objects per transaction (default
1000). Since the server acquires a lock per LO removed, removing
too many LOs in one transaction risks exceeding
max_locks_per_transaction. Set the limit to zero if you want all
removals done in a single transaction.

Don’t remove anything, just show what would be done.

Write a lot of progress messages.

Print the vacuumlo version and exit.

Show help about vacuumlo command line arguments, and exit.

vacuumlo also accepts the following command-line arguments for
connection parameters:

-h hostname
Database server’s host.

-p port
Database server’s port.

-U username
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 vacuumlo to prompt for a password before connecting to a

This option is never essential, since vacuumlo will automatically
prompt for a password if the server demands password
authentication. However, vacuumlo 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.

vacuumlo works by the following method: First, vacuumlo builds a
temporary table which contains all of the OIDs of the large objects in
the selected database. It then scans through all columns in the
database that are of type oid or lo, and removes matching entries from
the temporary table. (Note: Only types with these names are considered;
in particular, domains over them are not considered.) The remaining
entries in the temporary table identify orphaned LOs. These are


Peter Mount

PostgreSQL 9.5.5 2016 VACUUMLO(1)