Aggregates

[Former Member]

1. Can we create aggregates on Hierarchy ?

2. Can we compress the data in aggregates/ will the data in aggregates are compressed?

3. What is the Thumb rule of aggregates?

4. By creating aggregates how much percentage increase query performance ?

5. How to find which aggregates are more usage &which are less usage?

6. How to find which aggregates are in regular usage?

7. Aggr are created on char info object but how to find out based on which char we need to create?

Please explain me in a Detail manner.

[Former Member]

Thanks for your answers.

[Former Member]

Hi,

Yes you can create Aggregates based on hierarchy level.

Check the below document:

http://help.sap.com/saphelp_nw70/helpdata/en/44/70f4bb1ffb591ae10000000a1553f7/frameset.htm

http://help.sap.com/saphelp_nw70/helpdata/en/10/244538780fc80de10000009b38f842/frameset.htm

Reg

Pra

[Former Member]

1. yes you can use hierarchy level for creating aggregates in your cube.

2. yes, you have the option "roll and compress" in roll on tab.

3. * Do not create useless aggregates, because they are real cubes and contain data on your database.

• Make use of aggregate hierarchy for performance.

• observe your aggregations, fill and usage rates.

4. 5. 6.It all depends on your queries and aggregation definitions, and data volume. right click on your infocube and choose "maintain aggregates" .

there you can find, some statistical data about your aggregates. It shows how many records are aggregated to how many records in your aggregate.

This can be the basic start point to evaluate your aggregate. If you have 10000 records in your cube, and 8000 records in your aggregate, this would not be very helpfull.

Moreover, lets assume you have a good rate for aggregation of data, this may not still be a good aggregate if it is not used. ( usage time ).

All the filed agrgegates are used by OLAP, unless you switch them off for queries.

for a specific query, you can use debug option in RSRT to see if any aggregates are used during query run.

7. you can make use of statistical data (by proposals). Also check sql definition of your queries that has bad performance.

on maintain aggregates screen, choose "propose -->propose from query" steps.

Hope this helps.

Derya