Hello
2009/9/7 Tomasz Karlik <Tomasz.Karlik@ultimo.pl>:
>
>
>>>> Alvaro Herrera <alvherre@commandprompt.com> 9/4/2009 7:23 PM >>>
> tkarlik@ultimo.pl wrote:
>
>> Without casting function executes much slower:
>>
>> CREATE OR REPLACE FUNCTION table_exists(tblname text) RETURNS boolean AS=
'
>> DECLARE
>> exists boolean;
>> BEGIN
>>=C2=A0=C2=A0=C2=A0=C2=A0 SELECT 1 INTO exists FROM pg_class WHERE relname=
=3D name($1);
>>=C2=A0=C2=A0=C2=A0=C2=A0 RETURN exists;
>> END;
>> ' LANGUAGE 'plpgsql' IMMUTABLE;
>
it some strange. What version do you use?
on 5.4
postgres=3D# explain select * from pg_class where relname=3D'aaa';
QUERY PLAN
---------------------------------------------------------------------------=
-----
-------------
Index Scan using pg_class_relname_nsp_index on pg_class (cost=3D0.00..8.2=
7 rows=3D
1 width=3D185)
Index Cond: (relname =3D 'aaa'::name)
(2 rows)
the casting is implicit.
regards
Pavel Stehule
> If you're looking for a speedy answer, try a SQL function, not plpgsql.
>
>
> The same issue when using SQL function... However other casting (for exam=
ple
> int4->int8) works properly.
>
