OBIEE Year ago and Month ago

Question

Hi,
I want to find the month ago and year ago in obiee repository.I have measure column 'Sum(Sales)' and time hierarchy with year,month and date level. Note that I may not have data for all the dates since for some days I may not have any sales at all. If I use Ago function in repository with measure and month level, I am not getting result which I expected.
Please point me to correct directions.
Edited by: 961013 on Oct 1, 2012 7:42 AM

Answer 1

It sounds like you are on the right track. The lack of some fact records for specific dates should not matter. The Time Series Functions in the RPD are totally reliant on the time dimension being setup correctly, so I would first suggest checking the time dimension (hierarchy) setup. A common problem is with level-based keys. Check that keys have been defined correctly at each hierarchy level (except the Grand Total level); make sure that you have a sequential chronological key* defined at each dimension level, primary and drill down keys have been defined at each level (as required) and the grand total level has been correctly flagged. Don't forget, the dimension needs to be flagged as a time dimension too! There is plenty of guidance on the web about setting up and using time dimensions if you need more detail.
* If you think about this laterally, the time series functions need to know how to work out what a measure value was x periods ago. Periods could be years, months, weeks, quarters; as defined by the level variable in the time series function. So, based on a prompted period, say Mar-2012, the BI server does not have any inbuilt calendar logic that knows that two periods ago it was Jan-2012. Our calendar could be defined using some strange period names e.g JN10-11, FB10-11, MR11-12 etc. We need to tell the BI server how these periods are sequentially (or chronalogically) related. This is where the chronological keys come in which we define in the dimension.
Also, ensure that the aggregation method of the base measure is Sum.
Check the syntax you are using for the time series function:-
AGO(measure, time dimension level, number of period(s) ago) e.g. AGO(Core."Fact - Project Cost".Cost, Core."Date - Fiscal Calendar"."Fiscal Period", 1)
Do you get any RPD consistency check errors? Have you created a logical join between the fact and the dimension tables in the business model?
Finally, have you looked at the physical SQL being generated to get some pointers? You can do this by ensuring that the log level variable is set appropriately to display physical SQL in the query logs (e.g. level 2).
Please mark helpful/answered if this has been useful,
Andy.