Re: Hash index todo list item

On Thu, Sep 06, 2007 at 01:08:59PM -0500, Kenneth Marshall wrote:
> Since we already have to check the actual tuple values for any index
> lookup in postgresql, we could only store the full hash value and the
> corresponding TIDs in the bucket. Then when we lookup an item by
> calculating its hash, if the exact hash is not present in the bucket,
> then we know that the item is not in the index.

Sounds like you'd be returning a bitmap for use with a bitmap scan.
That's a different take on other suggestions I've heard and would allow
a hash index to have an almost unlimited key size yet flexible
matching... (combined with other index, or even just the same index).

Neat.

Have a nice day,
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to litigate.