Re: Forcing a specific order
От | Martin Foster |
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Тема | Re: Forcing a specific order |
Дата | |
Msg-id | 434C674A.9070700@ethereal-realms.org обсуждение исходный текст |
Ответ на | Re: Forcing a specific order (Michael Fuhr <mike@fuhr.org>) |
Ответы |
Re: Forcing a specific order
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Список | pgsql-novice |
Michael Fuhr wrote: > > It's not clear how you'd use a sort order to run concurrent queries, > nor how that involves how many rows you'd have to fetch. Could you > elaborate? But it might be better to post the query and the EXPLAIN > ANALYZE output and let others take a look: let's examine the problem > before thinking about a solution. > I should have been a bit more clear on the matter. Order by is useful if you want to sort the dataset a specific way using rows. However, what if I wanted to specify the order the rows are returned in using information from another query? While I could post table definitions, explain analyze information and sample data it probably is not all that useful. Lets just say that this three-way join is mixing a reverse index with two other tables. So trying to mix in VERY large datasets into one another with SUM and COUNT thrown in creates a nasty situation even if I would normally pick up at the most 100 rows. So my solution is to simplify matters and cut down the dataset used almost immediately. Even with say 24 secondary queries to fetch specific information this process is probably a lot cleaner? Martin Foster Creator/Designer Ethereal Realms martin@ethereal-realms.org
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