Page 1 of 1

Hash Partition to lookup stages

Posted: Sun Nov 27, 2011 10:57 pm
by SURA
Hi there

DS 8.5.01 64 Bit
OS Win2008 R2
DB SQL Server

I am trying to load the History data into prod and the job aborted due to the below error. Drive is having 1.5 TB space.

Code: Select all

Could not map table file "F:/IBM/Datasets/lookuptable.20111128.vfu1wld (size 653663296 bytes)": Not enough space 
Job design
2 source with join stage and then 5 lookup stages before load the data.

I managed to run the job by did the below steps.

1. Increased the no of nodes
2. Referred the diff drive scratch disk
3. Did hash partition to all the lookup stages (It was designed with Auto Partition).

Now the question is: For the first lookup if i choose hash and for the rest of the lookup did i get the same result in the target?

The reason for my doubt is,

First lookup need two columns from the source to do the lookup, say COLA, COLB. I did the HASH partition and selected COLA,COLB; that means hash partition will allocate the data in each nodes based on COLA, COLB.

Now If i select the same partition for the rest of the lookup, but i dropped the COLA,COLB after lookup 1 is done. In that case how the hash partition will handle the data?

Sorry, i can't visualize !!

It would be great of any one can help me in this!

Thanks
DS User

Posted: Sun Nov 27, 2011 11:03 pm
by meet_deb85
Please provide the information about the number of rows in your reference links for the lookup stage....

Posted: Sun Nov 27, 2011 11:07 pm
by SURA
Yes that i an important point.

few lookup is having less than million and the rest are with millions.

DS User

Posted: Mon Nov 28, 2011 2:14 am
by paultechm
Split the job as two separate jobs ,after join write into a dataset

Posted: Mon Nov 28, 2011 3:26 am
by BI-RMA
Using Lookup-Stage for millions of rows is not a very good design, because DataStage will first try to keep the complete Lookup-Dataset in memory and will then swap data to disk.

You had better use Left-Join instead.