Re: 335 times faster (!)

> ------- Ursprungligt meddelande -------
>
> Från: Mario Weilguni <mweilguni(at)sime(dot)com>
> Datum: Mon, 3 Feb 2003 20:05:48 +0100
>
>try:
>explain select * from enheter where enhetsid = '200178146';
>or
>explain select * from enheter where enhetsid = 200178146::bigint
>

explain select * from enheter where enhetsid = '200178146';
QUERY PLAN ---------------------------------------------------------------------------
Index Scan using pk_enheter on enheter (cost=0.00..4.05 rows=1 width=91)
Index Cond: (enhetsid = 200178146::bigint)
(2 rows)

Strange...using:
200178146::bigint
or
'200178146'
..the query is lightning fast. Since the PK column is of integer type, I don't think it's logical to pass a string-type argument...or am I different than most people on this point? :)

What about third party frameworks (such as Hibernate, eg) - I'm sure they will look at the column datatype and think: 'Oh, it's an integer...I'll pass an integer argument then', which will result in unnecessary poor performance.

What's the cause of this behaviour? Why isn't psql (or the backend) converting integer type arguments into char/string types, if there's this much to gain?

(Sorry for being quite a Pg newbie..have never used Pg for such "heavy" load before)

- Mikael

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