Re: Seq Scan

Ok, my bad.
But why this happens:
# explain ANALYZE select id from table_name where id>200000;
                                                                 QUERY PLAN

--------------------------------------------------------------------------------------------------------------------------------------------
 Index Scan using table_name_pkey on table_name  (cost=0.00..2618.96
rows=68960 width=4) (actual time=220.543..1479.495 rows=66730 loops=1)
   Index Cond: (id > 200000)
 Total runtime: 1504.839 ms
(3 rows)

dun=# explain ANALYZE select id from table_name where id>10;
                                                      QUERY PLAN
----------------------------------------------------------------------------------------------------------------------
 Seq Scan on table_name  (cost=0.00..9268.12 rows=266703 width=4)
(actual time=107.935..2733.592 rows=266720 loops=1)
   Filter: (id > 10)
 Total runtime: 2833.744 ms
(3 rows)


It uses Index Scan for id>200000 and Seq Scan for id>10?!

On 6/1/07, Joshua D. Drake <jd@commandprompt.com> wrote:

> Nothing. You have to scan the table because you aren't giving postgresql
> anything to use the index by.
>
> Joshua D. Drake
>