Book Image

Real Time Analytics with SAP Hana

By : Vinay Singh
Book Image

Real Time Analytics with SAP Hana

By: Vinay Singh

Overview of this book

SAP HANA is an in-memory database created by SAP. SAP HANA breaks traditional database barriers to simplify IT landscapes, eliminating data preparation, pre-aggregation, and tuning. SAP HANA and in-memory computing allow you to instantly access huge volumes of structured and unstructured data, including text data, from different sources. Starting with data modeling, this fast-paced guide shows you how to add a system to SAP HANA Studio, create a schema, packages, and delivery unit. Moving on, you’ll get an understanding of real-time replication via SLT and learn how to use SAP HANA Studio to perform this. We’ll also have a quick look at SAP Business Object DATA service and SAP Direct Extractor for Data Load. After that, you will learn to create HANA artifacts—Analytical Privileges and Calculation View. At the end of the book, we will explore the SMART DATA access option and AFL library, and finally deliver pre-packaged functionality that can be used to build information models faster and easier.
Table of Contents (16 chapters)
Real Time Analytics with SAP HANA
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

JOINS in SAP HANA


To address some specific business cases and have improved execution, SAP HANA introduces some additional JOINS on top of existing SQL JOINS. These SAP HANA specific JOINS are as follows:

  • Referential JOIN

  • Text JOIN

  • Temporal JOIN

  • Star JOIN

  • Spatial JOIN

Let's see the scenarios when we should consider using these SAP HANA specific JOINS :

Type

Scenario / use case

Remarks

Referential JOIN

Facts with matching dimensions only where referential integrity is ensured.

It's the default join type in SAP HANA.

Facts returned are dependent on queried attributes.

Text JOIN

Multi language table.

Needs a language column.

Behaves as the left outer join.

Temporal JOIN

A key date within a validity period.

Acts as a referential join.

Star JOIN

Star schema scenarios.

Needs data organized in a star schema.

All attributes and hierarchies are included.

Spatial join

Geospatial data.

Only available in calculation views.