> On Wed, Mar 15, 2006 at 09:36:04AM -0700, Brendan Duddridge wrote: >> Hi, >> >> Is it possible to put an index on an array column? > > Apparently yes (I just did it as a test). However, consider the > following from the manual. > > Tip: Arrays are not sets; searching for specific array elements > may be a sign of database misdesign. Consider using a separate > table with a row for each item that would be an array element. This > will be easier to search, and is likely to scale up better to large > numbers of elements.[1] > > Arrays are attractive, but it seems they most often aren't the best > solution. FOr instance, I beleive I read somewhere that the index > will be on the whole array, and the individual elements are not > indexed, so > > WHERE ary = {foo,bar} > > might benefit from your index, but > > WHERE 'foo' = ANY(ary) > > probably wouldn't. At least that's the impression I got from > reading the archives of this list. I haven't done any testing of > it. > > > -karl > > > > 1. http://www.postgresql.org/docs/8.0/interactive/arrays.html#AEN5491 > >> >> Thanks, >> >> ____________________________________________________________________ >> Brendan Duddridge | CTO | 403-277-5591 x24 | brendan@clickspace.com >> >> ClickSpace Interactive Inc. >> Suite L100, 239 - 10th Ave. SE >> Calgary, AB T2G 0V9 >> >> http://www.clickspace.com >> > > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: explain analyze is your friend >
Regards, Oleg _____________________________________________________________ Oleg Bartunov, Research Scientist, Head of AstroNet ( www.astronet.ru), Sternberg Astronomical Institute, Moscow University, Russia Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/ phone: +007(495)939-16-83, +007(495)939-23-83
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