Yongjun Zhang has posted comments on this change. ( http://gerrit.cloudera.org:8080/12213 )
Change subject: IMPALA-7929. Impala query on HBASE table failing with InternalException. ...................................................................... Patch Set 2: I found that even if I comment out the code at https://github.com/apache/impala/blob/1c94450ca92606fb6b708de2ea07445cc6610dbf/be/src/exec/hbase-table-scanner.cc#L394 and it still works, which seems mysterious. After some study, I found out why: when no filters are passed to hbase, impala get the all rows from hbase, then impala evaluate the predicates itself See https://github.infra.cloudera.com/CDH/Impala/blob/cdh6.x/be/src/exec/hbase-scan-node.cc#L252 This does the filtering for the predicates that involve column that has no qualifier. It's not very efficient, because we get back all rows from hbase scan, and filter out majority. It would be nice to have hbase to filter before returning to impala. Given this understanding, I think We can create a separate jira to address this performance issue, and push the fix forward. Thanks. -- To view, visit http://gerrit.cloudera.org:8080/12213 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: comment Gerrit-Change-Id: I378c2249604481067b5b1c3a3bbb28c30ad4d751 Gerrit-Change-Number: 12213 Gerrit-PatchSet: 2 Gerrit-Owner: Yongjun Zhang <[email protected]> Gerrit-Reviewer: Impala Public Jenkins <[email protected]> Gerrit-Reviewer: Joe McDonnell <[email protected]> Gerrit-Reviewer: Paul Rogers <[email protected]> Gerrit-Reviewer: Tim Armstrong <[email protected]> Gerrit-Reviewer: Yongjun Zhang <[email protected]> Gerrit-Comment-Date: Sun, 20 Jan 2019 05:33:50 +0000 Gerrit-HasComments: No
