Question:
Hi Folks,
There are certain points of concern I have been facing from quite some time now. I would appreciate if anyone of you guys could help me out in finding out the answers for these questions.
1- When partitioning the E table into X number of partitions, would each partition have 65GB? Or the 65GB will be divided between the X number of partitions.
2- The scenario is, a cube, is partitioned based on (0CALYEAR), and an aggregate is also created with 0CALYEAR included. Does the "E" table for this aggregate (assuming compression is set for aggregates in this cube) is partitioned as well?
3- When refreshing statistics for a partitioned cube, are partitioned table refreshed as well?
4- Can the partitions be placed in different table spaces?
5- Would realignment be optimized for partitioned cubes with aggregates? Or there not difference as today?
Well pls. help me out guys.
Thanks
GDW
Answer:
#1: Neither. Partitioning does not allocation disk.
BW360 - Business Information Warehouse: BW Performance & Administration, page 8-19 fifth bullet point: Don't worry about space in the database: partitioning does not allocate empty space. Instead it determines a way of grouping data as it is loaded into the fact table.
#2: Yes
BW360 - Business Information Warehouse: BW Performance & Administration, page 8-19 second bullet point: Aggregates are also partitioned like the InfoCube if they contain the partitioning characteristic. Even if the InfoCube is never compressed and the aggregates are, partitioning can improve performance.
I don't have/know the answers to #3 - #5 but I hope the first two help.
Answer:
I think you need to be a bit careful on getting this info from BW for question 1. The DBA's at our firm are telling me each partition is allocated with a maximum size of 4gig when we use BW to do this for us. I'm not aware of anywhere within BW that we can influence that size. DB2 will allow each partition to be allocated up to 64gig but something in BW is currently preventing that.
Your answer to question number 2 is perfect.
Appreciate ur concern Thanks!!
BWSupport