Re: Retiring is_pushed_down

On Tue, Jul 25, 2023 at 3:39 PM Richard Guo <guofenglinux@gmail.com> wrote:

> * This patch calculates the outer join relids that are being formed
> generally in this way:
>
>     bms_difference(joinrelids, bms_union(outerrelids, innerrelids))
>
> Of course this can only be used after the outer join relids has been
> added by add_outer_joins_to_relids().  This calculation is performed
> multiple times during planning.  I'm not sure if this has performance
> issues.  Maybe we can calculate it only once and store the result in
> some place (such as in JoinPath)?
>

In the v2 patch, I added a member in JoinPath to store the relid set of
any outer joins that will be calculated at this join, and this would
avoid repeating this calculation when creating nestloop/merge/hash join
plan nodes.  Also fixed a comment in v2.

Thanks
Richard