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In SSAS,need to create dimension? RRS feed

  • Question

  • Hi,

    I am new to SSAS, my question is as when we create DSV we already mention Measures and dimension.

    Suppose we want to create hierarchy in dimension then I understand the purpose of creating Dimension.

    But if we don't want to create any Hierarchy,then why we need to create Dimension when it is already present in DSV.

    Sunday, November 5, 2017 8:58 AM

Answers

  • Hi,

    DSV is used to define the specific tables that are retrieved from the data source and to give you control over the data structures used in your project, and to work independently of the underlying data sources (for example, the ability to rename or concatenate columns without directly modifying the original data source). 

    A Dimension in a cube is an Instance of a Database Dimension. An analogy, this is pretty similar to an Object (Instance of a Class) in a Programming Language.

    It is very important to create the dimensions in the cube and their relations with the Facts otherwise your dimension is not gonna be visible in your cube from the dsv.

    See more informations about the dimension from this article :

    https://www.mssqltips.com/sqlservertip/2683/sql-server-analysis-services-interview-questions-on-dimensions-hierarchies-and-properties/


    Please mark as answered, If you feel happy with this answer.

    • Marked as answer by Khushboo dubey Tuesday, November 7, 2017 6:34 AM
    Sunday, November 5, 2017 11:17 AM
  • Hi Khushboo,

    Thanks for your question.

    >>>my question is as when we create DSV we already mention Measures and dimension.Suppose we want to create hierarchy in dimension then I understand the purpose of creating Dimension.But if we don't want to create any Hierarchy,then why we need to create Dimension when it is already present in DSV.

    The DSV defines the logical layout of the data sources and the bindings define which tables, rows, and columns Analysis Services should use to populate the cubes. The objects in DSV are Dimension tables and Fact tables. Dimension tables contain details about each instance of an object. For example, the items dimension table would contain a record for each item sold in the store. It might include information such as the cost of the item, the supplier, color, sizes, and similar data.Fact tables and dimension tables are related to each other.

    A database dimension is a collection of related objects, called attributes, which can be used to provide information about fact data in one or more cubes, attributes are exposed to end users through attribute hierarchies. A hierarchy defines the relative position of attribute members in a dimension. By default,every attribute can form its own attribute hierarchy and dimensions are the containers for these hierarchies. Dimension may also contain user hierarchies which act as navigational paths to help the user in exploring the data from various angles.  Cubes contain all the dimensions on which users base their analyses of fact data. An instance of a database dimension in a cube is called a cube dimension and relates to one or more measure groups in the cube. A database dimension can be used multiple times in a cube.

    For more detailed information about attribute hierarchy and user hierarchy, please refer to below articles:
    https://docs.microsoft.com/en-us/sql/analysis-services/multidimensional-models-olap-logical-dimension-objects/attributes-and-attribute-hierarchies
    https://docs.microsoft.com/en-us/sql/analysis-services/multidimensional-models-olap-logical-dimension-objects/user-hierarchies


    Best Regards
    Willson Yuan
    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com


    Monday, November 6, 2017 3:10 AM
    Moderator

All replies

  • Hi,

    DSV is used to define the specific tables that are retrieved from the data source and to give you control over the data structures used in your project, and to work independently of the underlying data sources (for example, the ability to rename or concatenate columns without directly modifying the original data source). 

    A Dimension in a cube is an Instance of a Database Dimension. An analogy, this is pretty similar to an Object (Instance of a Class) in a Programming Language.

    It is very important to create the dimensions in the cube and their relations with the Facts otherwise your dimension is not gonna be visible in your cube from the dsv.

    See more informations about the dimension from this article :

    https://www.mssqltips.com/sqlservertip/2683/sql-server-analysis-services-interview-questions-on-dimensions-hierarchies-and-properties/


    Please mark as answered, If you feel happy with this answer.

    • Marked as answer by Khushboo dubey Tuesday, November 7, 2017 6:34 AM
    Sunday, November 5, 2017 11:17 AM
  • Hi Khushboo,

    Thanks for your question.

    >>>my question is as when we create DSV we already mention Measures and dimension.Suppose we want to create hierarchy in dimension then I understand the purpose of creating Dimension.But if we don't want to create any Hierarchy,then why we need to create Dimension when it is already present in DSV.

    The DSV defines the logical layout of the data sources and the bindings define which tables, rows, and columns Analysis Services should use to populate the cubes. The objects in DSV are Dimension tables and Fact tables. Dimension tables contain details about each instance of an object. For example, the items dimension table would contain a record for each item sold in the store. It might include information such as the cost of the item, the supplier, color, sizes, and similar data.Fact tables and dimension tables are related to each other.

    A database dimension is a collection of related objects, called attributes, which can be used to provide information about fact data in one or more cubes, attributes are exposed to end users through attribute hierarchies. A hierarchy defines the relative position of attribute members in a dimension. By default,every attribute can form its own attribute hierarchy and dimensions are the containers for these hierarchies. Dimension may also contain user hierarchies which act as navigational paths to help the user in exploring the data from various angles.  Cubes contain all the dimensions on which users base their analyses of fact data. An instance of a database dimension in a cube is called a cube dimension and relates to one or more measure groups in the cube. A database dimension can be used multiple times in a cube.

    For more detailed information about attribute hierarchy and user hierarchy, please refer to below articles:
    https://docs.microsoft.com/en-us/sql/analysis-services/multidimensional-models-olap-logical-dimension-objects/attributes-and-attribute-hierarchies
    https://docs.microsoft.com/en-us/sql/analysis-services/multidimensional-models-olap-logical-dimension-objects/user-hierarchies


    Best Regards
    Willson Yuan
    MSDN Community Support
    Please remember to click "Mark as Answer" the responses that resolved your issue, and to click "Unmark as Answer" if not. This can be beneficial to other community members reading this thread. If you have any compliments or complaints to MSDN Support, feel free to contact MSDNFSF@microsoft.com


    Monday, November 6, 2017 3:10 AM
    Moderator