SelfLearning of SSAS 01

OLAP(online analytical processing),and there are 3 advantages:

1.Continuous fast response.

Because the values that needed is pre-calculated before the query,then these values can be queryed directly.

The tools of OLAP can be divide to 2 basic models:

EXCEL and DataBase(most)

But if the number of dimension is big,It may cause data explosion by EXCEL.

DataBase model can avoid the data explosion by polymerize table(聚合表，sum,avg,ect)

2.The query based on Metadata

Query by MDX(MultiDimensional Expression)

3.The formula of EXCEL

eg:

C14/D12(EXCEL)

[Actual]/[Budget](MDX)