Re: Storing computed values
От | Richard Broersma |
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Тема | Re: Storing computed values |
Дата | |
Msg-id | 396486430804211221y6da92fadi9782b730bb119354@mail.gmail.com обсуждение исходный текст |
Ответ на | Re: Storing computed values (Colin Wetherbee <cww@denterprises.org>) |
Ответы |
Re: Storing computed values
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Список | pgsql-general |
On Mon, Apr 21, 2008 at 11:19 AM, Colin Wetherbee <cww@denterprises.org> wrote: > My impression of functional indexes is that they're useful mostly in WHERE > queries, like the following. > > SELECT foo, bar, baz FROM some_table WHERE lower(foo) = 'qux'; > > In this case, the index would be created on lower(foo). > > How would I get the value of the functional index out of the index in my > case? If this is the case, and you use Natural Foreign Keys, you only need to select from your foo table: SELECT Connect( location1, location2) FROM Foo WHERE location1 = ... OR location2 = ... OR connect(location1,location2) = ...; --this is where the functional index would be useful -- Regards, Richard Broersma Jr.
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