Tomasz Rybak <tomasz.ry...@post.pl> 于2024年5月31日周五 04:21写道：
> On Tue, 2024-04-23 at 16:59 +0800, Tender Wang wrote: > > > [ cut ] > > > > I have rebased master and fixed a plan diff case. > > We (me, Paul Jungwirth, and Yuki Fujii) reviewed this patch > at PgConf.dev Patch Review Workshop. > Thanks for reviewing this patch. > Here are our findings. > > Patch tries to allow for using materialization together > with parallel subqueries. > It applies cleanly on 8fea1bd5411b793697a4c9087c403887e050c4ac > (current HEAD). > Tests pass locally on macOS and Linux in VM under Windows. > Tests are also green in cfbot (for last 2 weeks; they were > red previously, probably because of need to rebase). > > Please add more tests. Especially please add some negative tests; > current patch checks that it is safe to apply materialization. It would > be helpful to add tests checking that materialization is not applied > in both checked cases: > 1. when inner join path is not parallel safe > 2. when matpath is not parallel safe > I added a test case that inner rel is not parallel safe. Actually, matpath will not create if inner rel is not parallel safe. So I didn't add test case for the second scenario. This patch tries to apply materialization only when join type > is not JOIN_UNIQUE_INNER. Comment mentions this, but does not > explain why. So please either add comment describing reason for that > or try enabling materialization in such a case. > Yeah, Richard commented the v1 patch about JOIN_UNIQUE_INNER in [1] * I think we should not consider materializing the cheapest inner path if we're doing JOIN_UNIQUE_INNER, because in this case we have to unique-ify the inner path. We don't consider material inner path if jointype is JOIN_UNIQUE_INNER in match_unsorted_order(). So here is as same logic as match_unsorted_order(). I added comments to explain why. [1] https://www.postgresql.org/message-id/CAMbWs49LbQF_Z0iKPRPnTHfsRECT7M-4rF6ft5vpW1ARSpBkPA%40mail.gmail.com -- Tender Wang OpenPie: https://en.openpie.com/
v4-0001-Support-materializing-inner-path-on-parallel-oute.patch
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