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From Mich Talebzadeh <>
Subject Re: Efficient filtering on Spark SQL dataframes with ordered keys
Date Tue, 01 Nov 2016 10:38:57 GMT
A bit of gray area here I am afraid, I was trying to experiment with it

According to

and I quote


registerTempTable() creates an in-memory table that is scoped to the
cluster in which it was created. The data is stored using Hive's
highly-optimized, in-memory columnar format."

So on the face of it tempTable is an in-memory table


Dr Mich Talebzadeh

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On 1 November 2016 at 10:01, Michael David Pedersen <> wrote:

> Hi again Mich,
> "But the thing is that I don't explicitly cache the tempTables ..".
>> I believe tempTable is created in-memory and is already cached
> That surprises me since there is a sqlContext.cacheTable method to
> explicitly cache a table in memory. Or am I missing something? This could
> explain why I'm seeing somewhat worse performance than I'd expect.
> Cheers,
> Michael

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