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Hive >> mail # user >> Partition performance


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Re: Partition performance
On Wed, Jul 3, 2013 at 5:19 AM, David Morel <[EMAIL PROTECTED]> wrote:

>
> That is still not really answering the question, which is: why is it slower
> to run a query on a heavily partitioned table than it is on the same number
> of files in a less heavily partitioned table.
>

According to Gopal's investigations in
https://issues.apache.org/jira/browse/HIVE-4051, each time Hive plans a
query, it does a query per a partition to the backing SQL database. That
would explain a lot of the latency for tables with large numbers of
partitions.

-- Owen