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_urlorder 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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