On Mon, Mar 27, 2017 at 12:08 PM, Teodor Sigaev <teodor@sigaev.ru> wrote:
> Improve performance of find_all_inheritors()
>
> Previous coding uses three nested loops which obviously were a pain for
> large number of table's children. Patch replaces inner loop with
> a hashmap.
>
> Author: Aleksander Alekseev
> Reviewed-by: me
>
> https://commitfest.postgresql.org/13/1058/
I'm a little worried that this will be noticeably slower when the
number of partitions is small, like 4 or 8 or 16. In other places,
we've found it necessary to support both a list-based strategy and a
hash-based strategy to avoid regressing small cases (e.g.
join_rel_list + join_rel_hash in PlannerInfo, ResourceArray in
resowner.c, etc).
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
