SAP HANA: Introduction to Data Modeling

Data Modeling

Data Modeling or Data Information Modeling is called Heart if HANA Application development. It helps to create views on tables and implement business logic to create reports. In SAP HANA Modeling we create Information views. Information modeling views are consumed by JAVA or HTML based applications. There are three types of Information views:

·         Attribute view

·         Analytic view

·         Calculation view.

Attribute view are the simplest type of views. Attribute views are used for Master data context. It is used to fetch data related to dimensions.

Analytic views are used to model data that includes measures e.g. an operational data mart representing sales order will include measures for quantity, sales order value etc.  are the fastest type of models. We can aggregate huge data like total quantity, number of cars sold etc. it used for creation of fact table.

Calculation views are used to perform complex calculations. It is combination of attribute view and analytic view. These can be defined either graphically or using SQL statements.

Attribute views are further of three types:

Standard attribute view

Derived attribute view

Time attribute view

Various type of joins are used in SAP HANA. HANA also uses some previous joins like inner and outer join and some are new joins.

                                                Primary Join

                                                Inner join                            Outer join

                                                                                Left outer Join                   Right outer join

In addition to this some specific joins are also used for SAP HANA like:

Referential Join:  This type of joins are used to ensure referential integrity i.e. to ensure that each foreign key value in table exits as primary key in referenced table.

Text Join: It is used to get language specific data e.g. one have id in different table and its description in another table and one want to view the same for that we use text join. It acts as left outer join.

Temporal Join: it is sort of referential join but provided with time interval. Like you want to fetch master and transactional data on the basis of time interval. In that case we use temporal join.

Star Join: It is used in calculation views. It is mainly used with Star Schema. It include all the hierarchies and attributes.

Spatial Join: It is used to join nodes in graphical calculations view to fetch data from data sources that have spatial data. It is performed using predicts such as intersects, crosses etc.