Warning before aggregation is osbsolete

[Former Member]

Hi guru's

I'm migrating our BW system and in some queries we have the message Warning calculation before aggregation is obsolete.

We still use BW 3.x analyzer.

when i execute queries the message is only a warning and i can see result in my reports.

i need to check the data but do you know if the message is a warning because this functionnality does not existe in BI 7 analyzer tool and if i use Bex 3.x will the data be correct ?

Thanks

Cyril

[Former Member · Accepted solution]

Good day Cyril,

When you migrate a query which has CKF with 'Before Aggregation', you will be requested to change it to 'after aggregation'. After turning on the option for 'After Aggregation query behaves same as what it used to do in BEx 3.5 with option 'B4 Ag'gregation'. Results are same.

The use of BEFORE aggregation was removed as this can cause a drain on the system resources and therefore cause performance problems. For this reason it was made obsolete with the 7.x system. The OLAP processor handles data differently in the 7.x systems so removing the before aggregation option should not cause too many problems for customers migrating over.

With this in mind, however, there are differences to BEFORE and AFTER aggregation. It may not affect the calculations you are using in your queries but you must be aware that some calculations are carried out at different times and this can cause hiccups. Most note-worthy would be when formulae are used and when replacement path variables are needed. In some cases, the necessary calculations may not be carried out and the figures may not be available which would not have been an issue in the 3.x system using before aggregation.

Check out SAP Note 1151957 which is excellent for understanding how the OLAP processor carries out calculations. It also details the differences between BEFORE and AFTER aggregation and should be very helpful for you going forward - particularly if you use formulae or replacement path functions.

Be aware that there are differences and there may be queries where you get a red X instead of a value. In most cases, this means rewriting a formula so that the processor can now accomodate the aggregation you need to achieve.

Hope this helps, Cyril.

Regards,

Karen

[Former Member]

Hi Karen, thanks for your reply

I check OSS NOtes that you described. i also check my data and it seems that in Bex Analyzer 3.x the query still correctly calculated even if i have the warning message.

I also check that if i use Bex Analyzer 3.x, there is no the solution of execption aggregation. this is a new functionnality with Bex 7.x.

I noted that before aggregation can generate poor performance.

Thanks for your reply.

CYril

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