Re: HASH Partitioning question

From: Deepak Sharma <>
Date: Fri, 13 Feb 2015 02:07:04 +0000
Message-ID: <>

It's a DW environment close to 150TB with almost 90% of tables partitioned, generating 6TB archive logs a day (24x7 loading with no batch window for loads).  

     On Thursday, February 12, 2015 8:02 PM, Deepak Sharma <> wrote:    

 Sure Tim (btw, I attended your DW seminar several years ago in Minneapolis and have implemented a few ideas that have really helped).

600gb table with 14 Billion rows. It's currently partitioned on a loading date column by range, and has a rolling window retention. Someone suggested changing it to HASH Partition on another column (lets say ABC) which is more frequently used, but may not have even distribution (so Range would have skewed data). My guess is that in order for the queries to use that new ABC HASH partitioned column (it could be equi-join, In-List etc.), PX is needed.

Let me know if you need more details.


     On Thursday, February 12, 2015 3:19 PM, Tim Gorman <> wrote:    

   C'mon, you need to give us more than that, please?   

 Query for one row?  Query for 10 million rows?  Aggregating?  Not aggregating?  Exadata or laptop or something in between?  Oracle7?  Oracle8i?  Windows?  Linux?  Android?      

 On 2/12/15 13:55, Deepak Sharma (Redacted sender for DMARC) wrote:   

 Is it true that if a table (say 1 billion rows) is HASH Partitioned, then the most efficient way to query it needs to use Oracle parallel threads ?                  

-- Received on Fri Feb 13 2015 - 03:07:04 CET

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