Before introducing calculation views in SAP HANA Cloud, you should become familiar with some key modeling concepts that are frequently used when creating calculation views.
Measure and Attribute
A data model is usually based on measures and attributes.
Measure Versus Attribute
|What is it?||Always a numeric value, such as a price or quantity, on which you can process arithmetic or statistics operations, such as sum, average, top N values, and calculations.||A descriptive element that is used with measures to provide meaningful information. For example 'Sales Revenue by <attribute>'.|
Attributes are used to filter or aggregate the measures, in order to answer questions such as the following:
What are the total sales originating from Hamburg?
What is the sales revenue for Cars by Month?
A dimension is a group of related attributes. In the example below, we have defined a dimension called Product. The dimension includes various attributes including product name, category, supplier.
Dimensions are re-useable objects and appear in star schemas.
A star schema is a very powerful type of data model that we can create in SAP HANA Cloud.
Watch this video to learn about the Star Schema.
A hierarchy is a structured representation of an organization, a list of products, the time dimension, and so on, using levels.
It is often used to provide easy navigation of a large data set in a drill-down.
Watch this video to learn about the hierarchy concept.
The term semantics is used to describe the meaning of an attribute or a measure. For example:
A monetary value
For example, the total amount sold would need to indicate the currency (for example USD, EUR, or GBP). Amount without a currency is meaningless.
A quantity, weight, volume, or distance
For example, the quantity would need to specify the unit of measurement in which the data is expressed. Again, a quantity without a unit of measurement is meaningless.