Question: What Is Referential Join In SAP HANA?

What is SAP HANA calculation view?

A calculation view is a flexible information view that you can use to define more advanced slices on the data available in the SAP HANA database.

Calculation views are simple and yet powerful because they mirror the functionality found in both attribute views and analytic views, and also other analytic capabilities..

How does Hana views improve performance?

Always follow – HANA Development PointsUse left outer joins maximum.Specify cardinality in joins (n:1 or 1:1) – only if sure.Set optimize join = true (only if cardinality is set like above)Use table functions instead of scripted calculation views.Execute in SQL-engine (for HANA live)More items…•

What is star join in Hana?

Star joins connect a central data entity to multiple entities that are logically related. You can create a graphical calculation view with star joins that join multiple dimensions to a single fact table.

What is referential join?

Referential Join is a join between two tables, which ensures that referential integrity is always maintained between the tables in question. Any record on the left will have a corresponding record on the right if the table on the right is taken into consideration.

What is the use of cardinality in SAP HANA?

Introduction. SAP HANA features like Calculation Views and CDS allow to specify the cardinality for joins to improve the performance of the execution. The cardinality specifies the number of rows which are matching another table if these tables are joined.

What is Information View in SAP HANA?

SAP HANA Modelling is an activity by which we create information view. Information View is similar to dimension, cube or information provider of BW. This information view is used for creating the multi-dimensional data model.

What is schema in SAP HANA?

A database schema enables you to logically group together objects such as tables, views, and stored procedures. Without a defined schema, you cannot write to the catalog. SAP HANA Extended Application Services (SAP HANA XS) enables you to create a database schema as a transportable design-time file in the repository.

What is text join in Hana?

Text Join is used in order to get language-specific data. Text Join is used to fetch the description based on user’s session language. Once we implement the text join in SAP HANA, it automatically find out user’s language and give description in that language.

What is join pruning in Hana?

Join pruning is a process where SAP HANA eliminates both tables and joins from its execution plan based how the joins are defined in the information view and how data is queried from the information view.

Which perspective is used to create joins?

Joins in SAP HANA are used for joining two or more tables having relevant data or records that creates a logical association between the tables. The joins are very important to bind the modeling object in a logical framework because these modeling objects are used for reporting and analytical purposes later.

How do you join tables in SAP?

Quickviewer / Query – Joining tables. There are 2 ways of joining tables in SAP: Inner and outer joins. If you have to following 2 tables, that you want to join, you see that there are 2 matching records: 11 and 12.

How fast is SAP HANA?

SAP HANA deployment empowers a business with a speed that is approximately 3600 times faster than that of the traditional databases. It comes with a multi-core parallel platform and assimilates even with complex databases like Hadoop. It puts a brand’s entire ERP into HANA, which is radical.

How do I get Hana views?

Create 2 Attribute Views on 2 Dim tables-Add output and activate both the views. Create 2 Analytical Views on Fact Tables → Add both Attribute views and Fact1/Fact2 at Data Foundation in Analytic view. Now Create a Calculation View → Dimension (Projection). Create Projections of both Analytical Views and Join them.

Which join is faster in SAP HANA?

Third, INNER JOIN will give you better performance compare to LEFT JOIN or LEFT OUTER JOIN. Another thing about JOINs and performance, you better use them on PRIMARY KEYS and not on each column. For me, both the time join with multiple fields is performing faster than join with concatenated fields.

What is dynamic join in SAP HANA?

Dynamic joins are special type of joins. In this join type, two or more fields from two data sources are joined using a join condition that changes dynamically based on the fields requested by the client. For example –Table1 and Table2 are joined on Field1 and Field2.

What is Star join?

A set of joins are considered to be a star join when a fact table (large central table) is joined to two or more dimension tables (smaller tables containing descriptions of the column values in the fact table). A Star join is comprised of 3 main parts: Semijoins.