>>> Pavel Stehule <pavel.stehule@gmail.com> 9/7/2009 3:47 PM >>>
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
>> SELECT 1 INTO exists FROM pg_class WHERE relname =3D name($1);
>> 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..8.27=
rows=3D
1 width=3D185)
Index Cond: (relname =3D 'aaa'::name)
(2 rows)
the casting is implicit.
=20
It does'nt work only inside function. Look for execution times in my first =
post. Maybe the planner treats SQL SELECT query other than procedural SELEC=
T INTO?
