Attribute relationships are one of the most important concepts in SSAS dimensions. They tell the cube how the data is structured and they are vital to query performance . ... This is the default behavior: every attribute is related to the key attribute (Reseller in this example).
What is a attribute relationship?
Attribute relationships are associations between attributes that specify how attributes are connected . Attribute relationships define how tables and columns are joined and used, and which tables are related to other tables. Without relationships, there is no interaction between data, and therefore no logical structure.
What are attributes in SSAS?
An attribute is bound to columns in one or more data source view tables or views . An attribute is always bound to one or more key columns, which determines the members that are contained by the attribute. By default, this is the only column to which an attribute is bound.
Why the attribute relations are required in the hierarchies in SSAS?
The Need for Attribute Relationships
They inform the processing engine about how the multi-dimensional data is structured and how the database needs to store the aggregated calculations . This information is necessary because if the data is not aggregated properly, then the performance of the cube will be impacted.
What is attribute in Cube?
Cube attributes provide information about the purpose of cubes . An example of a cube attribute is the CUBE_TYPE attribute. This attribute is used to indicate that a cube is a metrics cube. The value is METRICS. Another example of a cube attribute is CAPTION.
Can a relationship have an attribute?
Like entities, relationships can have attributes: we can define a sale to be a relationship between a customer entity (identified by the unique email address) and a given number of the product entity (identified by the unique product ID) that exists at a particular date and time (the timestamp).
What is the key attribute?
A key attribute is the unique characteristic of the entity . For ex. Name and hire date are attributes of the entity Employee.
Why do we use SSAS?
Microsoft SQL Server Analysis Services, SSAS, is an online analytical processing (OLAP) and data mining tool in Microsoft SQL Server. SSAS is used as a tool by organizations to analyze and make sense of information possibly spread out across multiple databases , or in disparate tables or files.
What are attribute hierarchies?
An Attribute Hierarchy is a Hierarchy created by SQL Server Analysis Services for every Attribute in a Dimension by default . ... For example, a Calendar Hierarchy contains Year, Quarter, Month, and Date as its levels.
What is measure in SSAS?
A measure is also commonly called a fact. ... A Measure Group is a collection/group of measures which belong to the same underlying fact table. In SSAS, typically each Measure Group is tied to each one of the underlying fact tables . A Measure is single numeric value whereas a Measure Group is a collection of measures.
What are hierarchies in SSAS?
A hierarchy is defines as the relative position of attribute members in a dimension. Every attribute form its own attribute hierarchy and dimensions are the containers for these hierarchies.
What is named query in SSAS?
A named query is a SQL expression represented as a table . In a named query, you can specify an SQL expression to select rows and columns returned from one or more tables in one or more data sources.
How do I create a date dimension in SSAS?
- In the ‘Main table’ combobox, select ‘Dim Date’
- keep ‘Key Columns’ unchanged (‘Date Key’ is already selected)
- In ‘Name Column’ combobox select ‘FullDateAlternateKey’
How do you deploy a dimension?
- Under the Actions menu, select Deploy and the specific model.
- Under the Actions menu, select Deploy All to make all changes at one time.
- Under the Model drop-down, select Deploy.
- Under the Application menu, select Deploy All. A message confirms the successful deployment.
What is an attribute of a dimension?
A dimension attribute is a column in a dimension table . Each attribute describes a level of summary within a dimension hierarchy. The dimension elements define the hierarchical relationships within a dimension table. The dimension attributes describe the dimension elements in terms that are familiar to users.
What is an SSAS cube?
An OLAP cube, also known as multidimensional cube or hypercube, is a data structure in SQL Server Analysis Services (SSAS) that is built, using OLAP databases, to allow near-instantaneous analysis of data. ... The useful feature of an OLAP cube is that the data in the cube can be contained in an aggregated form.
