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On Wed, 12 Dec 2007 14:25:16 -0800
"Medi Montaseri" <montaseri@xxxxxxxxx> wrote:
> Hi,
>
> I know this is not exactly admin related, but ... it is simple enough
> to be even fun
>
> From a performance point of view, is it better to use OR as in
> SELECT expr FROM expr WHERE col=this OR col=that OR col=theOther
> Or to use a range of values as in
> SELECT expr FROM expr WHERE col in ( val1, val2, ...., valn)
>
> I think the IN range yields a better query plan .... what do you
> think ? Thanks
Well a simple test:
postgres=# explain analyze select * from tellers where bid in ('1','2');
QUERY
PLAN
- ------------------------------------------------------------------------------------------------------
Seq Scan on tellers (cost=0.00..10.25 rows=20 width=352) (actual
time=0.019..0.192 rows=20 loops=1) Filter: (bid = ANY
('{1,2}'::integer[])) Total runtime: 0.314 ms (3 rows)
postgres=# explain analyze select * from tellers where bid = '1' or bid
= '2'; QUERY PLAN
- ------------------------------------------------------------------------------------------------------
Seq Scan on tellers (cost=0.00..11.50 rows=20 width=352) (actual
time=0.018..0.199 rows=20 loops=1) Filter: ((bid = 1) OR (bid = 2))
Total runtime: 0.275 ms
(3 rows)
postgres=#
> Medi
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