Re: Query not using index
От | Mitch Vincent |
---|---|
Тема | Re: Query not using index |
Дата | |
Msg-id | 00af01c0d987$b5f5a180$1251000a@windows обсуждение исходный текст |
Ответ на | Re: Query not using index (Stephan Szabo <sszabo@megazone23.bigpanda.com>) |
Список | pgsql-general |
Does that query really return 9420 rows ? If so, a sequential scan is probably better/faster than an index scan.. -Mitch ----- Original Message ----- From: <ryan@paymentalliance.net> To: <pgsql-general@postgresql.org> Sent: Thursday, May 10, 2001 9:22 AM Subject: Re: Query not using index > I vacuum every half hour! Here is the output from EXPLAIN: > > NOTICE: QUERY PLAN: > > Seq Scan on pa_shopping_cart (cost=0.00..7237.94 rows=9420 width=296) > > EXPLAIN > > Thanks! > > > On Thu, 10 May 2001 18:19:16 +0000 (UTC), > sszabo@megazone23.bigpanda.com (Stephan Szabo) wrote: > > > > >Have you vacuum analyzed recently and what does > >explain show for the query? > > > >On Thu, 10 May 2001 ryan@paymentalliance.net wrote: > > > >> Here's the query: > >> > >> SELECT > >> cart_row_id > >> FROM > >> pa_shopping_cart > >> WHERE > >> order_id = 20; > >> [ ... ] > >> There is an index on: > >> just order_id > >> just order_id and cart_row_id > >> and a PK on cart row_id > >> > >> I don't understand why it's not using one of these indexes! > >> Please post your responses to the group - my email is down. > > > > > >---------------------------(end of broadcast)--------------------------- > >TIP 2: you can get off all lists at once with the unregister command > > (send "unregister YourEmailAddressHere" to majordomo@postgresql.org) > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/users-lounge/docs/faq.html >
В списке pgsql-general по дате отправления: