Friday, 30 January 2015

SSIS-SSAS-SSRS Interview Questions and Answers (Part5)

21. What languages are used in SSAS ?
? Structured Query Language (SQL)
? Multidimensional Expressions (MDX) - an industry standard query language orientated towards analysis
? Data Mining Extensions (DMX) - an industry standard query language oriented toward data mining.
? Analysis Services Scripting Language (ASSL) - used to manage Analysis Services database objects.

22. How Cubes are implemented in SSAS ?
? Cubes are multidimensional models that store data from one or more sources.
? Cubes can also store aggregations
? SSAS Cubes are created using the Cube Wizard.
? We also build Dimensions when creating Cubes.
? Cubes can see only the DSV( logical View).

23. What is the difference between a derived measure and a calculated measure? 
The difference between a derived measure and a calculated measure is when the calculation is performed. A derived measure is calculated before aggregations are created, and the values of the derived measure are stored in the cube. A calculated measure is calculated after aggregations are created, and the values of a calculated measure aren’t stored in the cube. The primary criterion for choosing between a derived measure and a calculated measure is not efficiency, but accuracy.

24. What is a partition? 
A partition in Analysis Services is the physical location of stored cube data. Every cube has at least one partition by default. Each time we create a measure group, another partition is created. Queries run faster against a partitioned cube because Analysis Services only needs to read data from the partitions that contain the answers to the queries. Queries run even faster when partition also stores aggregations, the pre calculated totals for additive measures. Partitions are a powerful and flexible means of managing cubes, especially large cubes.

25. While creating a new calculated member in a cube what is the use of property called non-empty behavior? 
Nonempty behavior is important property for ratio calculations. If the denominator Is empty, an MDX expression will return an error just as it would if the denominator Were equal to zero. By selecting one or more measures for the Non-Empty Behavior property, we are establishing a requirement that each selected measure first be evaluated before the calculation expression is evaluated. If each selected measure is empty, then The expression is also treated as empty and no error is returned.
More Questions & Answers :-
Part1  Part2  Part3  Part4  Part5  Part6  Part7  Part8

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