Re: join over 12 tables takes 3 secs to plan
От | Hilmar Lapp |
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Тема | Re: join over 12 tables takes 3 secs to plan |
Дата | |
Msg-id | B3DCB6D1-1E95-11D7-9244-000393B4BFF6@gmx.net обсуждение исходный текст |
Ответ на | Re: join over 12 tables takes 3 secs to plan (Tom Lane <tgl@sss.pgh.pa.us>) |
Ответы |
Re: join over 12 tables takes 3 secs to plan
Re: join over 12 tables takes 3 secs to plan |
Список | pgsql-performance |
Thanks for the pointer Tom. The application that's generating those queries is open source, so I could even go in and hack the query generating code accordingly, but I doubt I can spare that time. Given the information in the document you pointed me at and Neil's email I assume there is no other immediate remedy. As an added note, appreciating that query optimization is a difficult problem, and I do think PostgreSQL is a great product. Having said that, I've written 16-table joins for Oracle and always found them to plan within a second or two, so that's why I thought there's nothing special about the query I posted ... I'm not saying this to be bashful about PostgreSQL, but rather to suggest that apparently there are ways to do it pretty fast. I'm only starting to use PostgreSQL and making experiences, so I'm asking for forgiveness what may occasionally seem to be ignorant ... -hilmar On Thursday, January 2, 2003, at 12:24 PM, Tom Lane wrote: > Hilmar Lapp <hlapp@gmx.net> writes: >> I have a query generated by an application (not mine, but there's >> nothing I can find that looks bad about the query itself) that takes >> an >> excessive amount of time to return even though there are almost no >> rows >> in the schema yet. > > Read > http://www.ca.postgresql.org/users-lounge/docs/7.3/postgres/explicit- > joins.html > > regards, tom lane > > -- ------------------------------------------------------------- Hilmar Lapp email: lapp at gnf.org GNF, San Diego, Ca. 92121 phone: +1-858-812-1757 -------------------------------------------------------------
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