[jira] [Commented] (HIVE-23959) Provide an option to wipe out column stats for partitioned tables in case of column removal
[ https://issues.apache.org/jira/browse/HIVE-23959?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17177586#comment-17177586 ] Yushi Hayasaka commented on HIVE-23959: --- [~kgyrtkirk] Thanks for the reply! I understood the key point and also confirmed the performance was improved through the test, replacing columns with a table which has 50+ partitions (timeout on HS2 -> 200 seconds after applying), on my environment. I was also concerned about calling `getPartitions` (slow function), but I found it did not call if we enabled the direct sql feature on this patch. Good! > Provide an option to wipe out column stats for partitioned tables in case of > column removal > --- > > Key: HIVE-23959 > URL: https://issues.apache.org/jira/browse/HIVE-23959 > Project: Hive > Issue Type: Improvement >Reporter: Zoltan Haindrich >Assignee: Zoltan Haindrich >Priority: Major > Labels: pull-request-available > Fix For: 4.0.0 > > Time Spent: 2h > Remaining Estimate: 0h > > in case of column removal / replacement - an update for each partition is > neccessary; which could take a while. > goal here is to provide an option to switch to the bulk removal of column > statistics instead of working hard to retain as much as possible from the old > stats. -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Commented] (HIVE-23959) Provide an option to wipe out column stats for partitioned tables in case of column removal
[ https://issues.apache.org/jira/browse/HIVE-23959?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17170498#comment-17170498 ] Yushi Hayasaka commented on HIVE-23959: --- Hello, I'm interested in dealing with the issue since we have difficulty with it. Just curious, how does it affect performance? Also, it seems to replace calling `clearColumnStatsState` instead of `updateOrGetPartitionColumnStats` for partitions. I think the performance improvement is here. Is it correct? Or does it have any other improvement too? > Provide an option to wipe out column stats for partitioned tables in case of > column removal > --- > > Key: HIVE-23959 > URL: https://issues.apache.org/jira/browse/HIVE-23959 > Project: Hive > Issue Type: Improvement >Reporter: Zoltan Haindrich >Assignee: Zoltan Haindrich >Priority: Major > Labels: pull-request-available > Time Spent: 1h 10m > Remaining Estimate: 0h > > in case of column removal / replacement - an update for each partition is > neccessary; which could take a while. > goal here is to provide an option to switch to the bulk removal of column > statistics instead of working hard to retain as much as possible from the old > stats. -- This message was sent by Atlassian Jira (v8.3.4#803005)
[jira] [Commented] (HIVE-23806) Avoid clearing column stat states in all partition in case schema is extended
[ https://issues.apache.org/jira/browse/HIVE-23806?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=17152623#comment-17152623 ] Yushi Hayasaka commented on HIVE-23806: --- Hello, I think this change does not improve the performance in case of dropping column, right? > Avoid clearing column stat states in all partition in case schema is extended > - > > Key: HIVE-23806 > URL: https://issues.apache.org/jira/browse/HIVE-23806 > Project: Hive > Issue Type: Improvement >Reporter: Zoltan Haindrich >Assignee: Zoltan Haindrich >Priority: Major > Labels: pull-request-available > Time Spent: 10m > Remaining Estimate: 0h > > in case there are many partitions; adding a new column without cascade may > take a while - because we want to make sure in schema evolution cases that we > don't reuse stats later-on by mistake... > however this is not neccessary in case the schema is extended -- This message was sent by Atlassian Jira (v8.3.4#803005)
