When do i need to process a cube?

2
votes

I have a SSAS 2008 Cube.

I've just inserted some more data (4 million transactions) in to the fact table and the dimensions are still good too. I've accidentally refreshed my Excel pivot table and noticed that my new data is there - I thought I had to reprocess the cube for this!!

That leaves me asking:

  1. When do I need to process the cube? Is it ONLY structural changes?
  2. When do I need to process dimensions?
  3. If I don't need to process the cube on inserting new data into source tables, what happens if I insert bad data into the source i.e. something that does not have a matching dimension key?
2
sql-serverssasolap-cube
I have edited your title. Please see, "Should questions include “tags” in their titles?", where the consensus is "no, they should not". - John Saunders
Thanks John - I'll take that on board. - Warren
What is the Storage Mode of your cube? Is it MOLAP? - Alex Peshik

2 Answers

2
votes

@Warren, I know it has been a while, but I have to say the issue you mentioned here is data latency issue. It depends on the storage mode you choose on your measure groups within your multidimensional cube. For example, it is ROLAP, there is no data latency issue, you do not need to re-process the cube. However, if it is MOLAP, which means, everything (i.e. data, metadata, and aggregations) is stored in the cube. Every time you do some ETL, you need to re-process it to show the updated data.

1
votes

You can process a cube under 3 conditions.

  1. If you are modifying the structure of the cube, you may be required to process the cube with the Full Process option.
  2. If you are adding new data to the cube, you can process the cube with the Incremental update option.
  3. To clear out and replace a cube's source data, you can use the Refresh data processing option.

Find more @ http://technet.microsoft.com/en-us/library/aa933573%28v=sql.80%29.aspx