On Thu, 8 Apr 2021 at 21:04, Amit Langote <amitlangot...@gmail.com> wrote: > + * These partition pruning steps come in 2 forms; operation steps and combine > + * steps. > > Maybe you meant "operator" steps? IIRC, the reason why we named it > PartitionPruneStepOp is that an op step is built to prune based on the > semantics of the operators that were involved in the matched clause. > Although, they're abused for pruning based on nullness clauses too. > Maybe, we should also updated the description of node struct as > follows to consider that last point:
Oh right. Thanks. I fixed that. > * PartitionPruneStepOp - Information to prune using a set of mutually ANDed > * OpExpr and any IS [ NOT ] NULL clauses > > + * Combine steps (PartitionPruneStepCombine) instruct the partition pruning > + * code how it should produce a single set of partitions from multiple input > + * operation steps. I didn't add that. I wasn't really sure if I understood why we'd talk about PartitionPruneStepCombine in the PartitionPruneStepOp. I thought the overview in gen_partprune_steps_internal was ok to link the two together and explain why they're both needed. > I think the last part should be: ...from multiple operation/operator > and [ other ] combine steps. Change that and pushed. David
