On 17 January 2018 at 23:48, Amit Langote <amitlangot...@gmail.com> wrote: > I'm concerned that after your patch to remove > match_clauses_to_partkey(), we'd be doing more work than necessary in > some cases. For example, consider the case of using run-time pruning > for nested loop where the inner relation is a partitioned table. With > the old approach, get_partitions_from_clauses() would only be handed > the clauses that are known to match the partition keys (which most > likely is fewer than all of the query's clauses), so > get_partitions_from_clauses() doesn't have to do the work of filtering > non-partition clauses every time (that is, for every outer row). > That's why I had decided to keep that part in the planner.
That might be better served by splitting classify_partition_bounding_keys() into separate functions, the first function would be in charge of building keyclauses_all. That way the remaining work during the executor would never need to match clauses to a partition key as they'd be in lists dedicated to each key. -- David Rowley http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services
