On Wed, Jan 22, 2025 at 6:15 PM Tom Lane <t...@sss.pgh.pa.us> wrote: > Really I'd think the right place to be fixing this is at a higher > level. Where are the repetitive find_ec_member_matching_expr calls > coming from?
I'm not aware of the repeated calls for the same child, and I mostly see it called once for every partition from prepare_sort_from_pathkeys(). For this case, fixing it at the high level would require something like MergeAppend building a mapping of Pathkey -> EM for all its children upfront, then passing this down to the prepare_sort_from_pathkeys(). The other patch series focuses on this being called from the generate_join_implied_equalities(). That call site could probably use the same approach with building a mapping before generating the partitionwise join paths.
