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Home > Archive > MS SQL Server OLAP > March 2006 > Performance and Aggregation questions
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Performance and Aggregation questions
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| yongli 2006-03-27, 3:29 am |
| I have two questions regarding how the aggregation design works in AS2005.
1. When you define attribute/user hierarchies in a dimension, by default
the relationship defined are flexible type, is this similar to the virtual
dimension in the AS2000 so that aggregation wizard will not consider
designing any aggregations on those attribute flexible hierarchies thus will
affect performance ultimately?
2. Is there a similar utility/method like PartitionAggregation
for AS2000
which allows to design and control your aggregation design on desired levels?
Thanks,
Yongli.
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| Akshai Mirchandani [MS] 2006-03-27, 8:27 pm |
| 1. The aggregation designer doesn't really take hierarchies into
consideration. It works on the attribute-based model -- therefore, if you
build good relationships between your attributes, you should see better
aggregations built.
Flexible relationships aren't a bad thing for query performance. But they
mean that aggregations will need to be re-processed if the dimensions are
being re-processed incrementally and the relationships are changing.
Rigid relationships avoid aggregations being re-processed on a
ProcessUpdate, but mean that the relationships cannot be changed at all
without a full processing of the dimension and cubes.
2. Not yet. There are some samples being worked on but they are not yet
available.
Thanks,
Akshai
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"yongli" <yongli@discussions.microsoft.com> wrote in message
news:FD732C12-4EEF-4622-9A79- E76D9A205946@microso
ft.com...
>I have two questions regarding how the aggregation design works in AS2005.
>
> 1. When you define attribute/user hierarchies in a dimension, by default
> the relationship defined are flexible type, is this similar to the virtual
> dimension in the AS2000 so that aggregation wizard will not consider
> designing any aggregations on those attribute flexible hierarchies thus
> will
> affect performance ultimately?
>
> 2. Is there a similar utility/method like PartitionAggregation
for AS2000
> which allows to design and control your aggregation design on desired
> levels?
>
> Thanks,
>
> Yongli.
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