Re: nested select query failing
От | amol |
---|---|
Тема | Re: nested select query failing |
Дата | |
Msg-id | 000a01c31f81$fa45da70$2e00a8c0@amol обсуждение исходный текст |
Ответ на | Re: nested select query failing (Stephan Szabo <sszabo@megazone23.bigpanda.com>) |
Список | pgsql-performance |
Hi Tom, U are great. As you have said, one item was numeric and another serial integer ) so it was applying seq scan. Thank you very much for your help everybody. regards, Amol ----- Original Message ----- From: "Tom Lane" <tgl@sss.pgh.pa.us> To: "amol" <amol@mithi.com> Cc: <pgsql-performance@postgresql.org> Sent: Tuesday, May 20, 2003 8:48 PM Subject: Re: [PERFORM] nested select query failing > "amol" <amol@mithi.com> writes: > > explain analyze select attached_info.id from attached_tag_list, > > attached_info > > where > > attached_tag_list.attached_tag = 265 > > and > > attached_tag_list.id = attached_info.id > > > NOTICE: QUERY PLAN: > > > Nested Loop (cost=0.00..165349.50 rows=114 width=16) (actual > > time=117.14..8994.60 rows=15 loops=1) > > -> Index Scan using ix_attached_tag_list_id on attached_tag_list > > (cost=0.00..111.13 rows=96 width=12) (actual time=0.12..0.66 rows=15 > > loops=1) > > -> Seq Scan on attached_info (cost=0.00..1211.53 rows=33553 width=4) > > (actual time=3.67..197.98 rows=33553 loops=15) > > Total runtime: 8994.92 msec > > > - I have already indexed attached_info on id using following query > > CREATE INDEX attached_info_Index_1 ON attached_info(id) ; > > Hm. I'd have expected an index scan too. Maybe the two id columns are > not of the same datatype? > > regards, tom lane > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org > >
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