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Hive QA commented on HIVE-20332: -------------------------------- Here are the results of testing the latest attachment: https://issues.apache.org/jira/secure/attachment/12934832/HIVE-20332.01.patch {color:red}ERROR:{color} -1 due to no test(s) being added or modified. {color:red}ERROR:{color} -1 due to 1 failed/errored test(s), 14865 tests executed *Failed tests:* {noformat} TestMiniDruidCliDriver - did not produce a TEST-*.xml file (likely timed out) (batchId=193) [druidmini_dynamic_partition.q,druidmini_test_ts.q,druidmini_expressions.q,druidmini_test_alter.q,druidmini_test_insert.q] {noformat} Test results: https://builds.apache.org/job/PreCommit-HIVE-Build/13103/testReport Console output: https://builds.apache.org/job/PreCommit-HIVE-Build/13103/console Test logs: http://104.198.109.242/logs/PreCommit-HIVE-Build-13103/ Messages: {noformat} Executing org.apache.hive.ptest.execution.TestCheckPhase Executing org.apache.hive.ptest.execution.PrepPhase Executing org.apache.hive.ptest.execution.YetusPhase Executing org.apache.hive.ptest.execution.ExecutionPhase Executing org.apache.hive.ptest.execution.ReportingPhase Tests exited with: TestsFailedException: 1 tests failed {noformat} This message is automatically generated. ATTACHMENT ID: 12934832 - PreCommit-HIVE-Build > Materialized views: Introduce heuristic on selectivity over ROW__ID to favour > incremental rebuild > ------------------------------------------------------------------------------------------------- > > Key: HIVE-20332 > URL: https://issues.apache.org/jira/browse/HIVE-20332 > Project: Hive > Issue Type: Improvement > Components: Materialized views > Reporter: Jesus Camacho Rodriguez > Assignee: Jesus Camacho Rodriguez > Priority: Major > Attachments: HIVE-20332.01.patch, HIVE-20332.patch > > > Currently, we do not expose stats over {{ROW\_\_ID.writeId}} to the optimizer > (this should be fixed by HIVE-20313). Even if we did, we always assume > uniform distribution of the column values, which can easily lead to > overestimations on the number of rows read when we filter on > {{ROW\_\_ID.writeId}} for materialized views (think about a large transaction > for MV creation and then small ones for incremental maintenance). This > overestimation can lead to incremental view maintenance not being triggered > as cost of the incremental plan is overestimated (we think we will read more > rows than we actually do). This could be fixed by introducing histograms that > reflect better the column values distribution. > Till both fixes are implemented, we will use a config variable that will set > the selectivity for filter condition on {{ROW\_\_ID}} during the cost > calculation. Setting that variable to a low value will favour incremental > rebuild over full rebuild. -- This message was sent by Atlassian JIRA (v7.6.3#76005)