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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML
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><TITLE
>LOAD</TITLE
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><HR
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><H1
>LOAD</H1
><DIV
CLASS="REFNAMEDIV"
><H2
>Name</H2
>LOAD &#8212; Dynamically loads an object file</DIV
><DIV
CLASS="REFSYNOPSISDIV"
><PRE
CLASS="SYNOPSIS"
><TT
CLASS="REPLACEABLE"
><I
></I
></TT
>
LOAD '<TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>'</PRE
><DIV
CLASS="REFSECT2"
><H3
>Inputs</H3
><P
></P
><P
></P
><DL
><DT
><TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
></DT
><DD
><P
>Object file for dynamic loading.&#13;</P
></DD
></DL
></DIV
><DIV
CLASS="REFSECT2"
><H3
>Outputs</H3
><P
>&#13;<P
></P
></P><DL
><DT
><SPAN
CLASS="RETURNVALUE"
>LOAD</SPAN
></DT
><DD
><P
>Message returned on successful completion.&#13;</P
></DD
><DT
><SPAN
CLASS="RETURNVALUE"
>ERROR:  LOAD: could not open file '<TT
CLASS="REPLACEABLE"
><I
>filename</I
></TT
>'</SPAN
></DT
><DD
><P
>Message returned if the specified file is not found. The file must be visible
<I
CLASS="EMPHASIS"
>to the <SPAN
CLASS="PRODUCTNAME"
>Postgres</SPAN
> backend</I
>,
with the appropriate full path name specified, to avoid this message.&#13;</P
></DD
></DL
><P>&#13;</P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><H2
>Description</H2
><P
>Loads an object (or ".o") file into the 
<SPAN
CLASS="PRODUCTNAME"
>Postgres</SPAN
> backend address space.  Once a
file is loaded, all functions in that file can be accessed.  This
function is used in support of user-defined types and functions.&#13;</P
><P
>If a file is not loaded using
<B
CLASS="COMMAND"
>LOAD</B
>, 
the file will be loaded automatically the first time the
function is called by <SPAN
CLASS="PRODUCTNAME"
>Postgres</SPAN
>.
<B
CLASS="COMMAND"
>LOAD</B
>
can also be used to reload an object file if it has been edited and
recompiled.  Only objects created from C language files are supported
at this time.&#13;</P
><DIV
CLASS="REFSECT2"
><H3
>Notes</H3
><P
>Functions in loaded object files should not call functions in other
object files loaded through the
<B
CLASS="COMMAND"
>LOAD</B
>
command. For example, all functions in file <TT
CLASS="LITERAL"
>A</TT
> should
call each other, functions in the standard or math libraries, or in
Postgres itself.  They should not call functions defined in a different
loaded file <TT
CLASS="LITERAL"
>B</TT
>.
  This is because if <TT
CLASS="LITERAL"
>B</TT
> is reloaded, the Postgres loader is
not able to relocate the calls from the functions in <TT
CLASS="LITERAL"
>A</TT
> into
the new address space of <TT
CLASS="LITERAL"
>B</TT
>.
If <TT
CLASS="LITERAL"
>B</TT
> is not reloaded, however, there will
not be a problem.&#13;</P
><P
>Object files must be compiled to contain position independent code.
For example, 
on DECstations you must use
<SPAN
CLASS="APPLICATION"
>/bin/cc</SPAN
>
with the <TT
CLASS="LITERAL"
>-G 0</TT
> option when compiling object files to be
loaded.&#13;</P
><P
>Note that if you are porting <SPAN
CLASS="PRODUCTNAME"
>Postgres</SPAN
>
 to a new platform, <B
CLASS="COMMAND"
>LOAD</B
>
will have to work in order to support ADTs.&#13;</P
></DIV
></DIV
><DIV
CLASS="REFSECT1"
><H2
>Usage</H2
><P
><PRE
CLASS="PROGRAMLISTING"
>--Load the file /usr/postgres/demo/circle.o
--
LOAD '/usr/postgres/demo/circle.o'</PRE
>
        </P
></DIV
><DIV
CLASS="REFSECT1"
><H2
>Compatibility</H2
><P
></P
><DIV
CLASS="REFSECT2"
><H3
>SQL92</H3
><P
>There is no <B
CLASS="COMMAND"
>LOAD</B
> in <SPAN
CLASS="ACRONYM"
>SQL92</SPAN
>.&#13;</P
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