Yifan Zhang has posted comments on this change. ( http://gerrit.cloudera.org:8080/18434 )
Change subject: KUDU-1644: Simplify InList predicate values based on rowset PK bounds ...................................................................... Patch Set 2: (2 comments) http://gerrit.cloudera.org:8080/#/c/18434/2//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/18434/2//COMMIT_MSG@11 PS2, Line 11: Also, the DRS bounds info can be used to skip rows : effectively when we have a predicate on a non-prefix of the primary key and the : leading column(s) have cardinality=1 (as described in KUDU-1291). > Was this implemented in this patch? I'm not sure I saw it. Yes, we can use the bound information to seek where we start to scan in a rowset. That makes us skipping rows or even a whole rowset. If we have two columns (a, b) in a rowset, the rowset has bound (1, 1) and (1,10), and we have a scan request with a predicate b >= 2. After optimizing ScanSpec, we will get the bound (1, 2) and (1, 10), and then we can use these bounds to get lower_bound_idx and upper_bound_idx, so we can scan at the row (1, 2). http://gerrit.cloudera.org:8080/#/c/18434/2/src/kudu/tablet/cfile_set.cc File src/kudu/tablet/cfile_set.cc: http://gerrit.cloudera.org:8080/#/c/18434/2/src/kudu/tablet/cfile_set.cc@439 PS2, Line 439: spec->SetLowerBoundKey(implicit_lb_key); > I'm confused about why we're able to modify the ScanSpec for every CFileSet Because we create a ScanSpec copy for each CFileSet Iterator: https://github.com/apache/kudu/blob/master/src/kudu/common/generic_iterators.cc#L1026 -- To view, visit http://gerrit.cloudera.org:8080/18434 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ia9c2aa958f19a0b62e40a2ef5eb5365f91cbab80 Gerrit-Change-Number: 18434 Gerrit-PatchSet: 2 Gerrit-Owner: Yifan Zhang <chinazhangyi...@163.com> Gerrit-Reviewer: Andrew Wong <aw...@cloudera.com> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Yifan Zhang <chinazhangyi...@163.com> Gerrit-Comment-Date: Wed, 04 May 2022 11:24:10 +0000 Gerrit-HasComments: Yes
