Hongjiang Zhang has posted comments on this change. ( http://gerrit.cloudera.org:8080/17773 )
Change subject: KUDU-1260: Fix prefetching bug on Java scanner ...................................................................... Patch Set 17: (1 comment) http://gerrit.cloudera.org:8080/#/c/17773/11//COMMIT_MSG Commit Message: http://gerrit.cloudera.org:8080/#/c/17773/11//COMMIT_MSG@10 PS11, Line 10: The writing thread records the timestamp of : its write, and the scanner thread creates two scanners (w and w/o prefetching), : by comparing the scan result of the two scanners, we can verify the : prefetching result. > Ack I have simplified some of the test. But when I tried to use one scanner to verify the prefetching feature. I found I required to get a list of List<pair<snapshot, rowCount>> during the writer inserts data. Then, for the scanner, it will know what is the expected row count for the specific snapshot after checking the pair<snapshot, rowCount>. I do not want to add an entry pair<snapshot, rowCount> for every insertion, so typically, I need to randomly insert some of them. On the scanner side, I have to randomly select one entry pair<snapshot,rowCount>. While this logic seems more complex than just using two scanners. Either recording the rowcount for a given snapshot, or using two scanners. Which method do you prefer? -- To view, visit http://gerrit.cloudera.org:8080/17773 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: kudu Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I853a041d86c75ec196d7d4ff45af4673c5c5f5cd Gerrit-Change-Number: 17773 Gerrit-PatchSet: 17 Gerrit-Owner: Hongjiang Zhang <[email protected]> Gerrit-Reviewer: Alexey Serbin <[email protected]> Gerrit-Reviewer: Andrew Wong <[email protected]> Gerrit-Reviewer: Grant Henke <[email protected]> Gerrit-Reviewer: Hongjiang Zhang <[email protected]> Gerrit-Reviewer: Kudu Jenkins (120) Gerrit-Comment-Date: Tue, 12 Oct 2021 08:02:11 +0000 Gerrit-HasComments: Yes
