Re: [HACKERS] path toward faster partition pruning

On Fri, Apr 6, 2018 at 11:38 PM, Alvaro Herrera <alvherre@alvh.no-ip.org> wrote:
> Yeah, there is one sentence there I didn't quite understand and would
> like to add it to the rewritten version of the comment before I remove
> the whole ifdeffed-out comment.
>
>  *      PARTCLAUSE_MATCH_STEPS: *clause_steps set to list of "partition pruning
>  *      step(s)" generated for the clause due to it being a BoolExpr or a
>  *      ScalarArrayOpExpr that's turned into one
>
> Exactly what does "ScalarArrayOpExpr that's turned into one" means?
> Does it mean we turn SAOP into BoolExpr?

Yes, we turn a ScalarArrayOpExpr into a BoolExpr and generate prune
step for the latter.  Maybe we'll have a base pruning step that can
process a ScalarArrayOpExpr directly someday.  We create base steps
only for OpExpr's for now.

> If you look at the rest of the rewritten comment, you'll notice some
> things probably need more explaining.  Wording suggestions welcome.

When I looked at it earlier today, I thought your rewrite looked much better.

Thanks,
Amit