# vacuumlo

vacuumlo — remove orphaned large objects from a PostgreSQL database

### Synopsis

`vacuumlo` \[*`option`*...] *`dbname`*...

### Description

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](https://www.postgresql.org/docs/10/static/lo.html) 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.

### Options

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](https://www.postgresql.org/docs/10/static/runtime-config-locks.html#GUC-MAX-LOCKS-PER-TRANSACTION). Set the limit to zero if you want all removals done in a single transaction.

`-n`

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

`-v`

Write a lot of progress messages.

`-V`\
`--version`

Print the vacuumlo version and exit.

`-?`\
`--help`

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.

`-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`

Force vacuumlo to prompt for a password before connecting to a database.

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.

### Notes

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 removed.

### Author

Peter Mount `<`[`peter@retep.org.uk`](mailto:peter@retep.org.uk)`>`