Re: Query plan optimization for CHECK NO INHERIT and single table?
От | Robert Haas |
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Тема | Re: Query plan optimization for CHECK NO INHERIT and single table? |
Дата | |
Msg-id | CA+Tgmobe3B41e00CEtSNw8L0j2im+jVun_NPcU2a_9Dt5AjGCQ@mail.gmail.com обсуждение исходный текст |
Ответ на | Query plan optimization for CHECK NO INHERIT and single table? (Matthias <nitrogenycs@gmail.com>) |
Список | pgsql-hackers |
On Thu, Aug 30, 2012 at 2:00 AM, Matthias <nitrogenycs@gmail.com> wrote: > Hey, > > I tried out the new CHECK NO INHERIT feature for inherited tables. > There seems to be an opportunity to generate slightly better query > plans sometimes. E.g. when I do > > SELECT * FROM base WHERE partition_id = 3 > > and there exists only one child table for which partition_id = 3 is > true I guess the query plan could just do a seq/index/whatever scan on > that table. Right now the query plan has an intermediate "Append" > node. This seems only useful if the results of multiple child tables > would need to be included. I think it's needed to translate between the child's set of attribute numbers and their parent's set of attribute numbers - that is, the child could have the columns in a different order, or could have extra ones. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
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