Re: Can't get two index scans

On Thu, Jun 23, 2016 at 8:47 AM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com> wrote:

> On Wed, Jun 22, 2016 at 9:36 PM, Craig James <cjames(at)emolecules(dot)com>
> wrote:
> > On Wed, Jun 22, 2016 at 11:36 AM, Jeff Janes <jeff(dot)janes(at)gmail(dot)com>
> wrote:
> ...
> But, JChem's cartridge is apparently not using a GiST index, which is
> what my first guess was. I can't really figure out what PostgreSQL
> API it is tapping into, so whatever it is very well might not support
> multi-column indexes at all.
>

They run a separate chemistry server process, which I believe is a Java
app. My guess (and it's strictly a guess) is that they use classic chemical
bitmap fingerprints, and the index scan runs in their separate process and
only returns the index-scan results.

Craig