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How to aggregate Fact Table with several combinaisons

Hi everyone
I'm working actually to populate data cube stored in a star shema.
I was able easily to populate my star shema, dimension and parent-child-dimensions (Thanks Talend :-) ).
But I have trouble to aggregate my fact tables because the only way I found to use the TAggregate is to input data selection into the process combinaisons by combinaisons.
It's fine with a datacube with few different combinaisons of aggregation but very time consumming with 152 different combinaisons.
Does someone use Talend to aggregate fact tables ?? How do you do it ??
I'm interesting by a way to produce the flow to aggregate many combinaisons of aggregation in the same way ???
3 REPLIES

Re: How to aggregate Fact Table with several combinaisons

Hi,
i would think that you are mixing things a little.
when you say 'populate data cube stored' - i understand that your OLAP server has a cube defined and its data is being supplied by you database (star schema).
but normally, there is no need for you to aggregate data into tables for that to happen.
what OLAP tool are you using?

Nicolas
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Re: How to aggregate Fact Table with several combinaisons

Hi,
There are many ways to do something Smiley Wink So' I'm not using OLAP server.
I'm working in geomatics domain and we need to use spatial data into our datacube and actually no OLAP server can support it nativelly with all the functionnalites we need. So we developped an OLAP client that is based on a preaggregated fact table. The OLAP client access to this star schema with SQL and return data. It is working like a ROLAP server but required to preaggregate all data combinaisons in to the fact table. The OLAP client is JMAP Spatial OLAP (http://www.kheops-tech.com/en/jmap/solap.jsp) and allows to build maps.
Generally we use a program developped with SAS 9.0 with many loops on PROC SUMMARY to populate the fact tables with aggregated data. But now I'm searching to perform the same process with Talend.

Re: How to aggregate Fact Table with several combinaisons

Really interesting project.
considering what you said you might consider creating an algorithm in SQL to create the aggregated tables instead of Talend.
could you post a link for me to read up on what tables/how are required?
thanks