On Tue, 16 Nov 2004 15:56:00 -0500, Tom Lane wrote:
> [... cut advice ...]
Thanks.
> How wedded are you to being able to say "IN"?
It's only a would-be-nice-to-have.
My dnaseq data type exploits the fact that DNA sequences are made from a
very small alphabet (four characters), so strings can be compressed/packed
4:1 while still being directly usable. A POSITION(dnaseq IN dnaseq) would
mean that the dnaseq-values don't have to be converted to text before
being searched.
But I can live with my existing DNASEQ_POSITION(dnaseq,dnaseq) solution
(which works directly on the dnaseq packed strings).
(I will also try to create a specialized index for long strings, hopefully
using some substring array algorithmics - but that's another story.)
--
Greetings from Troels Arvin, Copenhagen, Denmark