Ashwani Raina has posted comments on this change. ( http://gerrit.cloudera.org:8080/20546 )
Change subject: [compaction] Skip memory allocation for ancient undo deltas ...................................................................... Patch Set 1: (1 comment) http://gerrit.cloudera.org:8080/#/c/20546/1//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/20546/1//COMMIT_MSG@12 PS1, Line 12: removed from list of UNDO deltas in later stage of processing > What happens with such REDO deltas then? IIRC, UNDO deltas then garbage co Lifecycle of REDO deltas would remain the same as before. For each row index in a block (under processing), after the mutations are applied and REDOs are converted to UNDOs, whatever is left in REDO list is applied to the corresponding row. Usually, they may be nothing left in the REDO list, so at the end of compaction, we would only have list of UNDO deltas and base data containing the latest version. So, the life of a REDO delta would start at the time of delta memstore flush to disk up till compaction kicks in and converts them to UNDO deltas. As for in-memory representation of the REDO delta is concerned, its lifecycle will also remain the same i.e. will get allocated at the time allocating row block memory and deallocated after completion of each iteration of row block processing for compaction. -- To view, visit http://gerrit.cloudera.org:8080/20546 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: Ibb41636a3ac063478fe181560d4ec85dadeb0ef3 Gerrit-Change-Number: 20546 Gerrit-PatchSet: 1 Gerrit-Owner: Ashwani Raina <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Ashwani Raina <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Reviewer: Tidy Bot (241) Gerrit-Reviewer: Zoltan Martonka <[email protected]> Gerrit-Comment-Date: Tue, 10 Oct 2023 15:17:54 +0000 Gerrit-HasComments: Yes
