An attribute hierarchy is created for every attribute in a dimension, and each hierarchy is available for dimensioning fact data. This hierarchy consists of an “All” level and a detail level containing all members of the hierarchy.
you can organize attributes into user-defined hierarchies to provide navigation paths in a cube. Under certain circumstances, you may want to disable or hide some attributes and their hierarchies.
What is use of AttributeHierarchyDisplayFolder property ?
AttributeHierarchyDisplayFolder: Identifies the folder in which to display the associated attribute hierarchy to end users. For example if I set the property value as “Test” to all the Attributes of a dimension then a folder with the name “Test” will be created and all the Attributes will be placed into the same.
This is very important interview . The “Factless Fact Table” is a table which is similar to Fact Table except for having any measure; I mean that this table just has the links to the dimensions. These tables enable you to track events; indeed they are for recording events.
Factless fact tables are used for tracking a process or collecting stats. They are called so because, the fact table does not have aggregatable numeric values or information. They are mere key values with reference to the dimensions from which the stats can be collected
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What Is Fact Table?
A fact table contains the basic information that you wish to summarize. The table that stores the detailed value for measure is called fact table. In simple and best we can define as “The table which contains METRICS” that are used to analyse the business.
It consists of 2 sections
Foregine key to the dimesion
measures/facts(a numerical value that used to monitor business activity)
What Is Dimension Table?
A dimension table contains hierarchical data by which you’d like to summarize. A dimension table contains specific business information, a dimension table that contains the specific name of each member of the dimension. The name of the dimension member is called an “attribute”
The key attribute in the dimension must contain a unique value for each member of the dimension. This key attribute is called “primary key column”
The primary key column of each dimension table corresponding to the one of the key column in any related fact table.
How Will You Add A New Column To An Existing Table In Data Source View?
By using named calculations we can add a new column to an existing table in the data source view.
Why We Need Named Queries?
A named query is used to join multiple tables, to remove unnecessary columns from a table of a database. You can achieve the same in database using Views but this Named Queries will be the best bet whe you don’t have access to create Views in database.
What Is Named Query?
Named query in DSV is similar to View in Database. This is used to create Virtual table in DSV which will not impact the underlying database. Named query is mainly used to merge the two or more table in the datasource view or to filter columns of a table.
How Many Types Of Dimensions Are There And What Are They?
They are 3 types of dimensions
confirm dimension
junk dimension
degenerate attribute
How Many Types Of Attribute Relationships Are There?
They are 2 types of attribute relationships they are
Rigid
Flexible
Rigid: In Rigid relationships where the relationship between the attributes is fixed, attributes will not change levels or their respective attribute relationships.
Example: The time dimension. We know that month “January 2009” will ONLY belong to Year “2009” and it wont be moved to any other year.
Flexible : In Flexible relationship between the attributes is changed.
Example: An employee and department. An employee can be in accounts department today but it is possible that the employee will be in Marketing department tomorrow.
What Is Attribute Relationships, Why We Need It?
Attribute relationships are the way of telling the analysis service engine that how the attributes are related with each other. It will help to relate two or more attributes to each other.Processing time will be decreased if proper relationships are given. This increases the Cube Processing performance and MDX query performance too.
In Microsoft SQL Server Analysis Services, attributes within a dimension are always related either directly or indirectly to the key attribute. When you define a dimension based on a star schema, which is where all dimension attributes are derived from the same relational table, an attribute relationship is automatically defined between the key attribute and each non-key attribute of the dimension.
When you define a dimension based on a snowflake schema, which is where dimension attributes are derived from multiple related tables, an attribute relationship is automatically defined as follows
Between the key attribute and each non-key attribute bound to columns in the main dimension table.
Between the key attribute and the attribute bound to the foreign key in the secondary table that links the underlying dimension tables.
Between the attribute bound to foreign key in the secondary table and each non-key attribute bound to columns from the secondary table.
What Is Data Source View Or Dsv?
A data source view is a persistent set of tables from a data source that supply the data for a particular cube. BIDS also includes a wizard for creating data source views, which you can invoke by right-clicking on the Data Source Views folder in Solution Explorer.
Datasource view is the logical view of the data in the data source.
Data source view is the only thing a cube can see.
What Is Named Calculation?
A named calculation is a SQL expression represented as a calculated column. This expression appears and behaves as a column in the table. A named calculation lets you extend the relational schema of existing tables or views in a data source view without modifying the tables or views in the underlying data source.
Named calculation is used to create a new column in the DSV using hard coded values or by using existing columns or even with both.
What Is A Data Source Or Ds?
The data source is the Physical Connection information that analysis service uses to connect to the database that host the data. The data source contains the connection string which specifies the server and the database hosting the data as well as any necessary authentication credentials.
Explain The Flow Of Creating A Cube?
Steps to create a cube in ssas
Create a data source.
Create a datasource view.
Create Dimensions
Create a cube.
Deploy and Process the cube.
What Is Amo?
The full form of AMO is Analysis Management Objects. This is used to create or alter cubes from .NET code.
After Creating The Cube, If We Added A New Column To The Oltp Table Then How You Add This New Attribute To The Cube?
Just open the datasourceview and on right click we find the option REFRESH. Click the REFRESH then it will add new attributes to the table which can be added to Cube.
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