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><H1
><A
NAME="VACUUMLO"
></A
><SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
></H1
><DIV
CLASS="REFNAMEDIV"
><A
NAME="AEN153692"
></A
><H2
>Name</H2
>vacuumlo -- remove orphaned large objects from a <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> database</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><A
NAME="AEN153698"
></A
><H2
>Synopsis</H2
><P
><TT
CLASS="COMMAND"
>vacuumlo</TT
> [<TT
CLASS="REPLACEABLE"
><I
>option</I
></TT
>...] <TT
CLASS="REPLACEABLE"
><I
>dbname</I
></TT
>... </P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN153705"
></A
><H2
>Description</H2
><P
> <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> is a simple utility program that will remove any
<SPAN
CLASS="QUOTE"
>"orphaned"</SPAN
> large objects from a
<SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> database. An orphaned large object (LO) is
considered to be any LO whose OID does not appear in any <TT
CLASS="TYPE"
>oid</TT
> or
<TT
CLASS="TYPE"
>lo</TT
> data column of the database.
</P
><P
> If you use this, you may also be interested in the <CODE
CLASS="FUNCTION"
>lo_manage</CODE
>
trigger in the <A
HREF="lo.html"
>lo</A
> module.
<CODE
CLASS="FUNCTION"
>lo_manage</CODE
> is useful to try
to avoid creating orphaned LOs in the first place.
</P
><P
> All databases named on the command line are processed.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN153718"
></A
><H2
>Options</H2
><P
> <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> accepts the following command-line arguments:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-l</TT
> <TT
CLASS="REPLACEABLE"
><I
>limit</I
></TT
></DT
><DD
><P
> Remove no more than <TT
CLASS="REPLACEABLE"
><I
>limit</I
></TT
> large objects per
transaction (default 1000). Since the server acquires a lock per LO
removed, removing too many LOs in one transaction risks exceeding
<A
HREF="runtime-config-locks.html#GUC-MAX-LOCKS-PER-TRANSACTION"
>max_locks_per_transaction</A
>. Set the limit to
zero if you want all removals done in a single transaction.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-n</TT
></DT
><DD
><P
>Don't remove anything, just show what would be done.</P
></DD
><DT
><TT
CLASS="OPTION"
>-v</TT
></DT
><DD
><P
>Write a lot of progress messages.</P
></DD
><DT
><TT
CLASS="OPTION"
>-V</TT
><BR><TT
CLASS="OPTION"
>--version</TT
></DT
><DD
><P
> Print the <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> version and exit.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-?</TT
><BR><TT
CLASS="OPTION"
>--help</TT
></DT
><DD
><P
> Show help about <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> command line
arguments, and exit.
</P
></DD
></DL
></DIV
><P>
</P
><P
> <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> also accepts the following command-line
arguments for connection parameters:
<P
></P
></P><DIV
CLASS="VARIABLELIST"
><DL
><DT
><TT
CLASS="OPTION"
>-h</TT
> <TT
CLASS="REPLACEABLE"
><I
>hostname</I
></TT
></DT
><DD
><P
>Database server's host.</P
></DD
><DT
><TT
CLASS="OPTION"
>-p</TT
> <TT
CLASS="REPLACEABLE"
><I
>port</I
></TT
></DT
><DD
><P
>Database server's port.</P
></DD
><DT
><TT
CLASS="OPTION"
>-U</TT
> <TT
CLASS="REPLACEABLE"
><I
>username</I
></TT
></DT
><DD
><P
>User name to connect as.</P
></DD
><DT
><TT
CLASS="OPTION"
>-w</TT
><BR><TT
CLASS="OPTION"
>--no-password</TT
></DT
><DD
><P
> Never issue a password prompt. If the server requires password
authentication and a password is not available by other means
such as a <TT
CLASS="FILENAME"
>.pgpass</TT
> 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.
</P
></DD
><DT
><TT
CLASS="OPTION"
>-W</TT
></DT
><DD
><P
> Force <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> to prompt for a
password before connecting to a database.
</P
><P
> This option is never essential, since
<SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> will automatically prompt
for a password if the server demands password authentication.
However, <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> will waste a
connection attempt finding out that the server wants a password.
In some cases it is worth typing <TT
CLASS="OPTION"
>-W</TT
> to avoid the extra
connection attempt.
</P
></DD
></DL
></DIV
><P>
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN153796"
></A
><H2
>Notes</H2
><P
> <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> works by the following method:
First, <SPAN
CLASS="APPLICATION"
>vacuumlo</SPAN
> 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
<TT
CLASS="TYPE"
>oid</TT
> or <TT
CLASS="TYPE"
>lo</TT
>, 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.
</P
></DIV
><DIV
CLASS="REFSECT1"
><A
NAME="AEN153803"
></A
><H2
>Author</H2
><P
> Peter Mount <CODE
CLASS="EMAIL"
><<A
HREF="mailto:peter@retep.org.uk"
>peter@retep.org.uk</A
>></CODE
>
</P
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