Aggregates tables are important part of OBIA.I have
already dicussed about aggregator in my earlier posts "Aggregators".In
Datawarhouse we have to there will be many facts and we have to sum up fact data
with respect to a given dimension, for example by date(Date
dimension).
When we do these summations for
each facts it results in slowing down the performance of the mapping. Hence we
make use of the Aggregator to do these summations and other aggregate functions
like Min,Max,Avg etc.
OBIA pre calculates these sums and
stores it in the form of Aggregate tables. In OBIA the aggregate Tables are
suffixed using _A. You can easily identify an Aggregate table in OBIA using the
suffix.
Also there are many ways using
which you can improve the performance of the Aggregator which I have mentioned
in my previous posts.
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