Re: More Hashing questions

If you do this I suggest supporting bigint as well.

On Tue, May 04, 2004 at 06:45:37PM -0400, Greg Stark wrote:
>
> Regarding inter-data-type hash joins, would it make sense to make float
> datatypes to hash to the same value as integral data types for integral
> values?
>
> Conveniently this would cover the existing special case of -0 and +0 hashing
> to the same value. Something like this?
>
> Datum
> hashfloat4(PG_FUNCTION_ARGS)
> {
> float4 key = PG_GETARG_FLOAT4(0);
>
> if (key == (int32)key)
> PG_RETURN_UINT32(~(int32)key);
>
> return hash_any((unsigned char *) &key, sizeof(key));
> }
>
>
> Incidentally, why do all the floatfoo functions invert the value? It doesn't
> seem like that affects the quality of the hash at all.
>
>
> --
> greg
>
>
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