SAP C_ABAPD_2309 Dumps

A projection view is a RESTful Application Programming object that contains only the fields required for a particular app. A projection view is a CDS view entity that defines a projection on an existing CDS view entity or CDS DDIC-based view. A projection view exposes a subset of the elements of the projected entity, which are relevant for a specific business service. A projection view can also define aliases, virtual elements, and annotations for the projected elements. A projection view is the top-most layer of a CDS data model and prepares data for a particular use case. A projection view can have different provider contracts depending on the type of service it supports, such as transactional query, analytical query, or transactional interface.

A database view is a CDS DDIC-based view that defines a join or union of database tables. A database view has an SQL view attached and can be accessed by Open SQL or native SQL. A database view can be used as a projected entity for a projection view, but it does not contain only the fields required for a particular app.

A metadata extension is a RESTful Application Programming object that defines additional annotations for a CDS view entity or a projection view. A metadata extension can be used to enhance the metadata of a CDS data model without changing the original definition. A metadata extension does not contain any fields, but only annotations.

A data model view is a CDS view entity that defines a data model based on database tables or other CDS view entities. A data model view can have associations, aggregations, filters, parameters, and annotations. A data model view can be used as a projected entity for a projection view, but it does not contain only the fields required for a particular app.

References: CDS Projection Views - ABAP Keyword Documentation, CDS Projection Views in ABAP CDS: What’s Your Flavor, Business Object Projection - ABAP Keyword Documentation

Incomplete ABAP types are types that do not specify all the attributes of a data type, such as the length, the number of decimal places, or the value range. Incomplete types can only be used for the typing of field symbols and formal parameters, not for the definition of data objects or constants. Incomplete types can be either predefined or user-defined1.

The following are incomplete ABAP types:

C. C is a type for character strings with a generic length. The length of the character string has to be specified when a data object or a constant is defined with this type. For example, DATA text TYPE c LENGTH 10 defines a data object named text with a type c and a length of 10 characters2.

D. P is a type for packed numbers with a generic length and a generic number of decimal places. The length and the number of decimal places of the packed number have to be specified when a data object or a constant is defined with this type. For example, DATA amount TYPE p LENGTH 8 DECIMALS 2 defines a data object named amount with a type p, a length of 8 bytes, and 2 decimal places3.

The following are not incomplete ABAP types, because they specify all the attributes of a data type:

A. String is a type for variable-length character strings. The length of the character string is determined at runtime and can vary from 0 to 2,147,483,647 characters. The length does not have to be specified when a data object or a constant is defined with this type. For example, DATA text TYPE string defines a data object named text with a type string and a variable length4.

B. T is a type for time values in the format HHMMSS. The length of the time value is fixed at 6 characters and does not have to be specified when a data object or a constant is defined with this type. For example, DATA time TYPE t defines a data object named time with a type t and a length of 6 characters.

References: 1: Generic ABAP Types - ABAP Keyword Documentation 2: C - ABAP Keyword Documentation 3: P - ABAP Keyword Documentation 4: String - ABAP Keyword Documentation : T - ABAP Keyword Documentation

 Core Data Services (CDS) are preferable to the classical approach to data modeling for several reasons, but two of them are:

They implement code pushdown. Code pushdown is the principle of moving data-intensive logic from the application server to the database server, where the data resides. This reduces the data transfer between the application server and the database server, which improves the performance and scalability of the application. CDS enable code pushdown by allowing the definition of semantic data models and business logic in the database layer, using SQL and SQL-based expressions1.

They transfer computational results to the application server. CDS allow the application server to access the data and the logic defined in the database layer by using Open SQL statements. Open SQL is a standardized and simplified subset of SQL that can be used across different database platforms. Open SQL statements are translated into native SQL statements by the ABAP runtime environment and executed on the database server. The results of the computation are then transferred to the application server, where they can be further processed or displayed2.

References: 1: ABAP - Core Data Services (ABAP CDS) - ABAP Keyword Documentation 2: Open SQL - ABAP Keyword Documentation