Andrew Wong has posted comments on this change. ( http://gerrit.cloudera.org:8080/16752 )
Change subject: tablet: allow interleaving of row liveness between compaction input rows ...................................................................... Patch Set 3: (3 comments) http://gerrit.cloudera.org:8080/#/c/16752/2/src/kudu/tablet/compaction.cc File src/kudu/tablet/compaction.cc: http://gerrit.cloudera.org:8080/#/c/16752/2/src/kudu/tablet/compaction.cc@318 PS2, Line 318: // : // UNDO(del@5) <- BASE(a) -> REDO(del@10) -> REDO(reins@25) // main MR > Wondering what will happen if Addressed in the other comment. http://gerrit.cloudera.org:8080/#/c/16752/2/src/kudu/tablet/compaction.cc@390 PS2, Line 390: const Mutation* newer_row_last = left_newer ? left_last: right_last; > Just for my own understanding, wondering when this happen if all the ops ar They would all be assigned different timestamps, and we'd take the branch at L363. http://gerrit.cloudera.org:8080/#/c/16752/2/src/kudu/tablet/compaction.cc@453 PS2, Line 453: CopyMutations(Mutat > It seems for all REDOs in the 'older' that are greater than the REDO head o We discussed this on Slack, that I don't think it's a valid sequence in terms of how tablets generate mutations. For this to happen, the txn MRS would have to become "active" again at ts=40 and accept a write, but the transaction was committed already at ts=15 and thus stopped inserting new inserts. The delete at ts=20 was part of a different op, but landed in the transaction MRS because mutations attach themselves to where the latest live row is. I've added a comment explaining. Let me know if I can clarify more. -- To view, visit http://gerrit.cloudera.org:8080/16752 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I042a7d70d32edf9d2a3a077790821893f162880a Gerrit-Change-Number: 16752 Gerrit-PatchSet: 3 Gerrit-Owner: Andrew Wong <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Andrew Wong <[email protected]> Gerrit-Reviewer: Grant Henke <[email protected]> Gerrit-Reviewer: Hao Hao <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Comment-Date: Fri, 11 Dec 2020 07:15:36 +0000 Gerrit-HasComments: Yes
