CDS View in SAP ABAP ON HANA

 Q1-What is CDS Views? Why SAP Introduced CDS View ? What is the advantage of CDS Views over SE11 View ?

A-  Se11 Views-

1-It can be created from SAPGUI or Eclipse.
2. Calculated column are not possible.
3. Input Parameters are not possible.
4. Only Join is possible.
5. Grouping and aggregation are not possible.
6. Annotations are not possible.Annotations is used by UI5 Person in Front End .

CDS View 

. 1-It can only be created from Eclipse platform only.
2. Calculated columns are possible.

3-Following Functions are possible
A. Operator Function possible .
B. CDS Function possible
C. CASE Expression

D. Aggregated Functions

3. Input parameter is allowed and can be used  in calculated Columns
 4-Filtering Allowed .
4. Join and Union both are possible.
5. Grouping and aggregation are possible.
6. Annotation can be used to provide more metadata information to individual fields and Views.

So that's why SAP Introduced CDS Views.

In CDS Views

We are creating models in application layer (ECLIPSE) and it is going to create same in DB layer. Its like, we are using door of application layer to create objects/models in HANA DB.