You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@hbase.apache.org by "Lars Hofhansl (JIRA)" <ji...@apache.org> on 2018/04/21 17:41:00 UTC
[jira] [Commented] (HBASE-17958) Avoid passing unexpected cell to
ScanQueryMatcher when optimize SEEK to SKIP
[ https://issues.apache.org/jira/browse/HBASE-17958?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16446908#comment-16446908 ]
Lars Hofhansl commented on HBASE-17958:
---------------------------------------
Seems we god stuck here. [~vik.karma] did some comparative testing between 0.98 and 1.x and found a 50% slowdown for cases with many columns. This is a highly likely culprit.
> Avoid passing unexpected cell to ScanQueryMatcher when optimize SEEK to SKIP
> ----------------------------------------------------------------------------
>
> Key: HBASE-17958
> URL: https://issues.apache.org/jira/browse/HBASE-17958
> Project: HBase
> Issue Type: Bug
> Reporter: Guanghao Zhang
> Assignee: Guanghao Zhang
> Priority: Major
> Fix For: 1.4.0, 2.0.0
>
> Attachments: 0001-add-one-ut-testWithColumnCountGetFilter.patch, 17958-add.txt, HBASE-17958-branch-1.patch, HBASE-17958-branch-1.patch, HBASE-17958-branch-1.patch, HBASE-17958-branch-1.patch, HBASE-17958-v1.patch, HBASE-17958-v2.patch, HBASE-17958-v3.patch, HBASE-17958-v4.patch, HBASE-17958-v5.patch, HBASE-17958-v6.patch, HBASE-17958-v7.patch, HBASE-17958-v7.patch
>
>
> {code}
> ScanQueryMatcher.MatchCode qcode = matcher.match(cell);
> qcode = optimize(qcode, cell);
> {code}
> The optimize method may change the MatchCode from SEEK_NEXT_COL/SEEK_NEXT_ROW to SKIP. But it still pass the next cell to ScanQueryMatcher. It will get wrong result when use some filter, etc. ColumnCountGetFilter. It just count the columns's number. If pass a same column to this filter, the count result will be wrong. So we should avoid passing cell to ScanQueryMatcher when optimize SEEK to SKIP.
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)