On Mon, Jun 26, 2006 at 02:52:56AM -0700, pajai wrote: > I have thought of a possible workaround. I would like to know if it > seems reasonable. The idea would be to build a hash, on the client > side, over the problematic column (let's say column a). I then store in > the db the attribute a (without index) and the hash(a) (with an index). > Then when I am doing a select, I use firstly a sub-select to choose all > tuples with the right hash (quick, with index), and then an outer > select to choose the tuple with the right attribute a (slow, sequential > scan, but normally few tuples, because few collisions). Something like > that:
Perhaps you should look into functional indexes. Indexes over a function. CREATE INDEX foo_index ON foo( hash(a) ); This index will automatically be used if you make a query like this: ... WHERE hash(a) = 'blah'; Hope this helps, -- Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to > litigate.
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