Re: again on index usage

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От Tom Lane
Тема Re: again on index usage
Дата
Msg-id 23405.1010500631@sss.pgh.pa.us
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Ответ на Re: again on index usage  (Daniel Kalchev <daniel@digsys.bg>)
Ответы Re: again on index usage  (Daniel Kalchev <daniel@digsys.bg>)
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Daniel Kalchev <daniel@digsys.bg> writes:
> Same result (sorry, should have included this originally):

> Aggregate  (cost=47721.72..47721.72 rows=1 width=8)
>   ->  Seq Scan on iplog_gate200112  (cost=0.00..47579.54 rows=56873 width=8)

>>> If you say "set enable_seqscan to off", does that change the plan?

> Aggregate  (cost=100359.71..100359.71 rows=1 width=8)
>   ->  Index Scan using iplog_gate200112_ipdate_idx on iplog_gate200112  
> (cost=0.00..100217.52 rows=56873 width=8)

So, what we've got here is a difference of opinion: the planner thinks
that the seqscan will be faster.  How many rows are actually selected
by this WHERE clause?  How long does each plan actually take?
        regards, tom lane


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