SAP Updated C_HANADEV_18 Exam Questions and Answers by romy

To check user input data in your OData request, you need to use the Validation exit type. The Validation exit type is a custom exit that allows you to perform validation of input data and data consistency checks before, after, or during the change operation, or before or after the commit operation. You can specify a maximum of four validation exits per change operation; the exit is registered for the corresponding event with the respective keyword: “before”, “after”, “precommit” or “postcommit”. The validation exit is executed as an SQLScript procedure with a specific signature, and it can raise an error if the input data does not meet the validation criteria1.

The other options, Consistency, Modification, and Verification, are not exit types that you can use to check user input data in your OData request. Consistency is not an exit type, but a property that you can set in the OData service definition to enable or disable the consistency check for the change operations. The consistency check ensures that the data in the database is consistent with the data in the request payload2. Modification is an exit type that allows you to define custom logic to create, update, or delete an entry in an entity set. If a modification exit is specified, it is executed instead of the generic actions provided by the OData infrastructure1. Verification is not an exit type, but a process that you can perform to ensure that the OData service definition is valid and can be activated without errors3. References: 1: Custom Exits for OData Write Requests | SAP Help Portal 2: Consistency Check | SAP Help Portal 3: Verifying the OData Service Definition | SAP Help Portal

According to the SAP HANA Developer Guide, the resource path of an OData service URL identifies the entity or entity set that is requested. The resource path consists of the service root URI followed by a slash (/) and the name of the entity set. For example, to view all available products in the Products entity set, the resource path is /Products. The other options are incorrect, because:

• /Products/$metadata is not a valid resource path, but a system query option that returns the metadata document of the OData service.
• /Products/’ is not a valid resource path, but a syntax error. The single quotation mark is not needed after the entity set name.
• /Products/ALL is not a valid resource path, but a filter expression that can be used as a query option. The filter expression must be preceded by a question mark (?) and the $filter system query option. For example, /Products?$filter=ALL.

References: SAP HANA Developer Guide, Chapter 6, Section 6.4.2, page 2111.

When you create an HDI database role using the SAP Web IDE for SAP HANA, you define the role in a design-time file with the extension .hdbrole. This file is part of your project and can be deployed to the HDI container as a runtime role. However, if you make any changes to the runtime role directly in the database, such as granting or revoking privileges, those changes are not reflected in the design-time file. Therefore, if you change and re-build the design-time role, the runtime role will be overwritten with the new version of the design-time role, and any runtime modifications will be lost. This is because the deployment process always drops and recreates the runtime role based on the design-time role. The other options are incorrect because the deployment of the role will not fail, the runtime modifications will not be kept, and you do not need to confirm the runtime modifications. References:

• SAP HANA DI Administrator Roles - SAP Help Portal
• SAP HANA Deployment Infrastructure Reference - SAP Help Portal
• Modifying the default access_role in HDI containers - SAP Blogs

To create a native SAP HANA application that fully leverages the SAP HANA platform, you should implement data-intensive calculations on the database layer, using SQLScript or calculation views. SQLScript is a scripting language that allows you to write stored procedures, functions, and triggers that perform complex calculations and data transformations on the SAP HANA database. Calculation views are graphical or scripted views that define data models based on tables, views, or other calculation views, and apply filters, joins, aggregations, and other operations on the data. By pushing the calculations onto the database layer, you can take advantage of the in-memory processing, parallelization, and optimization capabilities of SAP HANA, and reduce the data transfer and network latency between the application layer and the database layer123.

The other options are not correct because they do not fully leverage the SAP HANA platform, and they may result in poor performance, high resource consumption, and increased complexity. Pushing the calculations onto the application layer means that you use a programming language, such as Java or Node.js, to perform the calculations on the application server, which may not be as efficient or scalable as the database server. Pushing the calculations onto the presentation layer means that you use a UI framework, such as SAPUI5 or SAP Fiori, to perform the calculations on the client device, such as a browser or a mobile device, which may not have enough processing power or memory to handle large or complex data sets. Distributing the calculations between the application layer and the presentation layer means that you split the calculations into different parts and execute them on different layers, which may introduce inconsistency, redundancy, and dependency issues. References:

• SAP HANA Platform, SAP HANA SQL and System Views Reference, SQLScript Guide
• SAP HANA Platform, SAP HANA Modeling Guide for SAP HANA Web Workbench, Calculation Views
• SAP HANA Platform, Developing Applications with SAP HANA Cloud Platform, Developing Multi-Target Applications, Developing Database Modules