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https://issues.apache.org/jira/browse/HIVE-13884?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15327768#comment-15327768
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Sergio Peña commented on HIVE-13884:
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[~brocknoland] What type of query would you prefer to test? This patch won't
allow a query to fetch all 100K partitions if
{{HiveConf.ConfVars.HIVELIMITTABLESCANPARTITION}} is set to a number > -1. If
it is not set, no query is executed to reques the # of partitions, so no
overhead will be added to it.
> Disallow queries fetching more than a configured number of partitions in
> PartitionPruner
> ----------------------------------------------------------------------------------------
>
> Key: HIVE-13884
> URL: https://issues.apache.org/jira/browse/HIVE-13884
> Project: Hive
> Issue Type: Improvement
> Reporter: Mohit Sabharwal
> Assignee: Sergio Peña
> Attachments: HIVE-13884.1.patch
>
>
> Currently the PartitionPruner requests either all partitions or partitions
> based on filter expression. In either scenarios, if the number of partitions
> accessed is large there can be significant memory pressure at the HMS server
> end.
> We already have a config {{hive.limit.query.max.table.partition}} that
> enforces limits on number of partitions that may be scanned per operator. But
> this check happens after the PartitionPruner has already fetched all
> partitions.
> We should add an option at PartitionPruner level to disallow queries that
> attempt to access number of partitions beyond a configurable limit.
> Note that {{hive.mapred.mode=strict}} disallow queries without a partition
> filter in PartitionPruner, but this check accepts any query with a pruning
> condition, even if partitions fetched are large. In multi-tenant
> environments, admins could use more control w.r.t. number of partitions
> allowed based on HMS memory capacity.
> One option is to have PartitionPruner first fetch the partition names
> (instead of partition specs) and throw an exception if number of partitions
> exceeds the configured value. Otherwise, fetch the partition specs.
> Looks like the existing {{listPartitionNames}} call could be used if extended
> to take partition filter expressions like {{getPartitionsByExpr}} call does.
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