overload

Hi,<br />while reading 20GB table through PL/PERL function , it constantly grows in RAM. <br />I wanted to ask you
whichis the best way to read table inside that  function without such memory consumption.<br />Thanks in advance<br
/><br/>Code is here:<br /><br />CREATE  FUNCTION pattern_counter("patLength" integer)<br />  RETURNS varchar AS<br
/>$BODY$<br/>    my $rv = spi_exec_query("select sequence from entry");<br />    my $rowCount = $rv->{processed};<br
/>    my $patLen = $_[0];<br />    my $patt = '';<br />    my %patterns=();<br />    foreach my $rn (0 .. $rowCount
-1){<br/>    my $row = $rv->{rows}[$rn];<br />    my $seq = $row->{sequence};<br />    for (my $x =
1;$x<=length($seq)- $patLen;$x++){<br />         $patt=substr($seq,$x,$patLen);<br />        if (! defined
$patterns{$patt}){<br />        $patterns{$patt}=1;<br />        }else{<br />        $patterns{$patt}++;<br />       
}<br/>    }<br />    }<br />    foreach $patt (keys %patterns){<br />     my $sql="insert into patterns
values('".$patt."',".$patterns{$patt}.")";<br/>    spi_exec_query($sql);<br />    }<br />return '';<br />$BODY$<br /> 
LANGUAGEplperl VOLATILE<br />  COST 100;<br /><br /><br clear="all" /><br />-- <br
/>---------------------------------------<br/>Viktor Bojović<br />---------------------------------------<br />Wherever
Igo, Murphy goes with me<br />