<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Global Values in PL/Perl</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 8.0.11 Documentation" HREF="index.html"><LINK REL="UP" TITLE="PL/Perl - Perl Procedural Language" HREF="plperl.html"><LINK REL="PREVIOUS" TITLE="Data Values in PL/Perl" HREF="plperl-data.html"><LINK REL="NEXT" TITLE="Trusted and Untrusted PL/Perl" HREF="plperl-trusted.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2007-02-02T03:57:22"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" >PostgreSQL 8.0.11 Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="plperl-data.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="plperl.html" >Fast Backward</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 37. PL/Perl - Perl Procedural Language</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="plperl.html" >Fast Forward</A ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="plperl-trusted.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="PLPERL-GLOBAL" >37.4. Global Values in PL/Perl</A ></H1 ><P > You can use the global hash <TT CLASS="VARNAME" >%_SHARED</TT > to store data, including code references, between function calls for the lifetime of the current session. </P ><P > Here is a simple example for shared data: </P><PRE CLASS="PROGRAMLISTING" >CREATE OR REPLACE FUNCTION set_var(name text, val text) RETURNS text AS $$ if ($_SHARED{$_[0]} = $_[1]) { return 'ok'; } else { return "can't set shared variable $_[0] to $_[1]"; } $$ LANGUAGE plperl; CREATE OR REPLACE FUNCTION get_var(name text) RETURNS text AS $$ return $_SHARED{$_[0]}; $$ LANGUAGE plperl; SELECT set_var('sample', 'Hello, PL/Perl! How's tricks?'); SELECT get_var('sample');</PRE ><P> </P ><P > Here is a slightly more complicated example using a code reference: </P><PRE CLASS="PROGRAMLISTING" >CREATE OR REPLACE FUNCTION myfuncs() RETURNS void AS $$ $_SHARED{myquote} = sub { my $arg = shift; $arg =~ s/(['\\])/\\$1/g; return "'$arg'"; }; $$ LANGUAGE plperl; SELECT myfuncs(); /* initializes the function */ /* Set up a function that uses the quote function */ CREATE OR REPLACE FUNCTION use_quote(TEXT) RETURNS text AS $$ my $text_to_quote = shift; my $qfunc = $_SHARED{myquote}; return &$qfunc($text_to_quote); $$ LANGUAGE plperl;</PRE ><P> (You could have replaced the above with the one-liner <TT CLASS="LITERAL" >return $_SHARED{myquote}->($_[0]);</TT > at the expense of readability.) </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="plperl-data.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="plperl-trusted.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Data Values in PL/Perl</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="plperl.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >Trusted and Untrusted PL/Perl</TD ></TR ></TABLE ></DIV ></BODY ></HTML >