| From: | "Merlin Moncure" <merlin(dot)moncure(at)rcsonline(dot)com> |
|---|---|
| To: | Ragnar Hafstað <gnari(at)simnet(dot)is> |
| Cc: | <pgsql-performance(at)postgresql(dot)org> |
| Subject: | Re: [SQL] OFFSET impact on Performance??? |
| Date: | 2005-01-20 19:29:34 |
| Message-ID: | 6EE64EF3AB31D5448D0007DD34EEB3412A75C8@Herge.rcsinc.local |
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| Thread: | |
| Lists: | pgsql-performance |
> this will only work unchanged if the index is unique. imagine , for
> example if you have more than 50 rows with the same value of col.
>
> one way to fix this is to use ORDER BY col,oid
nope! oid is
1. deprecated
2. not guaranteed to be unique even inside a (large) table.
Use a sequence instead.
create view a_b as
select nextval('some_sequnce')::k, a.*, b.* from a, b [...]
select * from a_b where k > k1 order by k limit 1000
*or*
execute fetch_a_b(k1, 1000) <-- pass limit into prepared statement for extra flexibility.
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