Re: store A LOT of 3-tuples for comparisons
От | Matthew |
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Тема | Re: store A LOT of 3-tuples for comparisons |
Дата | |
Msg-id | Pine.LNX.4.64.0802221546370.20402@aragorn.flymine.org обсуждение исходный текст |
Ответ на | store A LOT of 3-tuples for comparisons (Moritz Onken <onken@houseofdesign.de>) |
Ответы |
Re: store A LOT of 3-tuples for comparisons
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Список | pgsql-performance |
On Fri, 22 Feb 2008, Moritz Onken wrote: > I need to store a lot of 3-tuples of words (e.g. "he", "can", "drink"), order > matters! > The source is about 4 GB of these 3-tuples. > I need to store them in a table and check whether one of them is already > stored, and if that's the case to increment a column named "count" (or > something). My suggestion would be to use three varchar columns to store the 3-tuples. You should then create a B-tree index on the three columns together. > I thought of doing all the inserts without having an index and without doing > the check whether the row is already there. After that I'd do a "group by" > and count(*) on that table. Is this a good idea? That sounds like the fastest way to do it, certainly. Matthew -- "We have always been quite clear that Win95 and Win98 are not the systems to use if you are in a hostile security environment." "We absolutely do recognize that the Internet is a hostile environment." Paul Leach <paulle@microsoft.com>
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