Tender Wang <tndrw...@gmail.com> 于2025年4月24日周四 22:07写道：
> > > Tender Wang <tndrw...@gmail.com> 于2025年4月14日周一 14:17写道： > >> Hi, >> >> While I debug hashjoin codes, in estimate_multivariate_bucketsize(), I >> find that >> the list_copy(hashclauses) below is unnecessary if we have a single join >> clause. >> >> List *clauses = list_copy(hashclauses); >> ... >> >> I adjust the place of list_copy() call as the attached patch. >> This can save some overhead of function calls and memory copies. >> >> Any thoughts? >> >> > Hi Alexander, > > In the last thread, I found a minor optimization for the code in > estimate_multivariate_bucketsize(). > Adjust the place of list_copy() at the start of > estimate_multivariate_bucketsize, and we can avoid unnecessarily creating a > new list > and memory copy if we have only a single hash clause. > > Do you think it's worth doing this? > Hi all, I have added this patch to commitfest[1]. I'm hoping someone can review it for me. [1] https://commitfest.postgresql.org/patch/5704/ -- Thanks, Tender Wang
