using for rec inside a function: behavior very slow

I have a function:
CREATE FUNCTION hasdup(text) RETURNS int4 AS '
declare
v_id int4;
rat1 text;
rat2 text;
v_url text;
rec record;

begin
select id into v_id from urlinfo where url = $1;
if NOT FOUND then
return -1;
end if;
select codestr(v_id) into rat1;
v_url:= $1||''%'';
for rec in select id,url from urlinfo where url like v_url order by
url loop
raise notice ''%'',rec.url;
select codestr(rec.id) into rat2;
if rec.id <> v_id and rat1 = rat2 then
update urlinfo set list = 1 where id = rec.id;
return rec.id;
end if;
end loop;
return 0;
end;
' LANGUAGE 'plpgsql';

'where url like clause' is very slow in inside the function,
but when I directly use this statement in SQL, it is very quick,
is any quick way to return match:
where field like 'something%' inside the plsql function??

Jie LIANG

St. Bernard Software

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jliang(at)ipinc(dot)com
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