| From: | Stephan Szabo <sszabo(at)megazone23(dot)bigpanda(dot)com> |
|---|---|
| To: | Jeong Jaeick, 정재익 <advance(at)advance(dot)sarang(dot)net> |
| Cc: | pgsql-sql(at)postgresql(dot)org |
| Subject: | Re: Question about indexing! |
| Date: | 2001-10-02 16:32:33 |
| Message-ID: | Pine.BSF.4.21.0110020927590.46517-100000@megazone23.bigpanda.com |
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| Thread: | |
| Lists: | pgsql-sql |
On Tue, 2 Oct 2001, [euc-kr] Jeong Jaeick, wrote:
> select * from pgsql_bbs where topic = 'qna' and deleted < 2
> order by gid desc, pos asc limit 20, 0;
>
> But this query is not using index!
>
> The next is result of explain of this query:
>
> dsn=# explain select * from pgsql_bbs where topic = 'qna' and deleted < 2
> dsn-# order by gid desc, pos asc limit 20, 0;
> NOTICE: QUERY PLAN:
>
> Limit (cost=15.71..15.71 rows=11 width=245)
> -> Sort (cost=15.71..15.71 rows=11 width=245)
> -> Index Scan using pgsql_topic_deleted on pgsql_bbs (cost=0.00..15.51 rows=11 width=245)
It appears to be using the topic_deleted index according to this
explain output.
How many rows actually have topic='qna' and deleted<2?
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