On Sat, Sep 08, 2007 at 06:56:23PM -0400, Mark Mielke wrote: > I think that if the case of >1 entry per hash becomes common enough to > be significant, and the key is stored in the hash, that a btree will > perform equal or better, and there is no point in pursuing such a hash > index model. This is where we are today.
There is the point that if a user does an UPDATE of a row without changing the key your index will have to store entries with the same hash. If your goal is mostly write-once tables, then that's cool, but otherwise you're going to have to find a way of dealing with that. It's not just going to happen a lot, it is going to be common, even for unique indexes. Presumably HOT will help with this, but that relies on all index columns not to change. The major benenfits will mostly come from not storing the key at all. I think. Have a nice day, -- Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/ > From each according to his ability. To each according to his ability to > litigate.
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