SCOM DW big size

Hi,

One of our customer has the SCOMDW database size > 300GB. Using the tool dwdatarp we got this result:

Dataset name                   Aggregation name     Max Age     Current Size, Kb
------------------------------ -------------------- ------- --------------------
...
Configuration dataset          Raw data                   30   395,665,704 ( 96%)
.....

I've already change the Max Age of Configuration dataset from default to 30 days, change the grooming interval to 5 minuts but it seems doesnt affect the Configuration dataset.

How could I reduce its size? Thanks.