Most Recent SAP C_HANADEV_18 Exam Dumps

OData associations are used to define the relationships between two or more entity types in an OData service. Associations can be simple or complex, depending on whether the relationship information is stored in one of the participating entities or in a separate association table. Associations are composed of two ends, each of which has a role name, a multiplicity, and a set of properties that form the referential constraint. The keywords that are used to define an OData association are:

DEPENDENT: This keyword is used to specify the role name of the dependent end of the association, which is the entity type that contains the foreign key properties that refer to the principal entity type. For example, in the association Customer_Orders, the entity type Orders is the dependent end, as it contains the property CustomerID that refers to the entity type Customers.

MULTIPLICITY: This keyword is used to specify the cardinality of each end of the association, which indicates how many instances of one entity type can be related to one instance of another entity type. The possible values for multiplicity are: 0...1 (zero or one), 1 (exactly one), or * (many). For example, in the association Customer_Orders, the multiplicity of the principal end Customers is 1, meaning that each customer can have only one instance, and the multiplicity of the dependent end Orders is *, meaning that each customer can have many orders.

PRINCIPAL: This keyword is used to specify the role name of the principal end of the association, which is the entity type that is referenced by the foreign key properties of the dependent entity type. For example, in the association Customer_Orders, the entity type Customers is the principal end, as it is referenced by the property CustomerID of the entity type Orders.

The following keywords are not used to define an OData association, but for other purposes:

JOIN: This keyword is used to specify the join condition between two entity sets in a query expression, which is used to retrieve data from multiple sources. For example, the query expression Customers?$expand=Orders($filter=Status eq 'Open') uses a join condition to filter the orders that have the status 'Open' for each customer.

UNION: This keyword is used to specify the union operation between two query expressions, which is used to combine the results of both queries into one result set. For example, the query expression Customers?$filter=Country eq 'US' union Customers?$filter=Country eq 'CA' uses a union operation to get the customers that are from either the US or Canada.

The package descriptor package.json is a JSON file that defines the build, deployment, and runtime dependencies of a JavaScript application in SAP HANA XS Advanced. The package.json file is mandatory for JavaScript applications and it is located in the general section of the project. As well as the application name and version, dependencies to other Node.js modules, the Node.js version, run scripts, and the main program are configured. The package descriptor package.json is used for the following purposes:

To list the package dependencies: The package.json file contains a dependencies property that lists the names and versions of the Node.js modules that the application depends on. These modules are installed by the npm install command during the build process and are available in the node_modules folder of the application. The dependencies property can also specify the scope and type of the dependencies, such as devDependencies for development-only modules, or peerDependencies for modules that are required by other modules.

To define the routes: The package.json file contains a sap.cloud.service property that defines the name of the service that the application provides or consumes. This name is used to generate the routes for the application in the XS advanced environment. The routes are defined in the xs-app.json file, which is located in the same folder as the package.json file. The routes specify the rules for forwarding requests to the back-end microservices or destinations.

The following purposes are not achieved by the package descriptor package.json, but by other files or tools:

To define back-end destinations: The back-end destinations are defined in the mta.yaml file, which is the deployment descriptor file that specifies the metadata and dependencies for the multi-target application (MTA) project. The mta.yaml file is located in the root folder of the MTA project and is used by the Cloud Foundry environment to deploy the application. The back-end destinations are declared as resources of type org.cloudfoundry.existing-service or org.cloudfoundry.managed-service, and are bound to the application modules by the requires property.

To set the router version: The router version is set by the @sap/approuter module, which is a Node.js module that provides the application router service for the XS advanced environment. The application router service is responsible for routing requests to the appropriate destinations and for authenticating users. The @sap/approuter module is installed by the npm install command during the build process and is available in the node_modules folder of the application. The version of the @sap/approuter module is specified in the dependencies property of the package.json file.

[SAP HANA Deployment Infrastructure Reference], Chapter 5: HDI with XS Advanced, Section 5.1: Developing with the SAP Web IDE for SAP HANA, Subsection 5.1.2: Configure Application Routing (xs-app.json), pp. 101-104.

[SAP HANA Platform Documentation], SAP HANA Developer Guide for SAP HANA XS Advanced Model, Chapter 4: Developing HTML5 Applications, Section 4.1: Developing HTML5 Applications Using SAP Web IDE for SAP HANA, Subsection 4.1.3: Configure Application Routing (xs-app.json), pp. 77-80.

An OData service is a web service that exposes data from a data source, such as a SAP HANA database, in a standardized and interoperable format. An OData service consists of one or more entity sets, which are collections of entities of the same type. An entity is a data object that has properties and a unique key. An OData service can also define associations between entity sets, which are relationships that specify how entities are related to each other. For example, an association can define a one-to-many or a many-to-many relationship between two entity sets. Associations enable an OData service to combine data from different database tables within the same service. For example, an OData service can define an association between a Products entity set and a Categories entity set, where each product belongs to one category and each category can have multiple products. This association can be used to query or update data from both entity sets in a single request.

The other options are incorrect because they are not capabilities that can be used to combine data from different database tables within an OData service. Aggregations are operations that summarize or group data, such as count, sum, average, or min/max. Projections are operations that select or filter data, such as select, expand, or filter. Entity sets are collections of entities of the same type, but they do not define relationships between entities.Reference:

SAP HANA Platform 2.0 SPS06: OData V4 Developer Guide, Section 2.1

SAP HANA Platform 2.0 SPS06: OData V4 Developer Guide, Section 2.3

SAP HANA Platform 2.0 SPS06: OData V4 Developer Guide, Section 2.4

SAP HANA Platform 2.0 SPS06: OData V4 Developer Guide, Section 2.5

SAP HANA Platform 2.0 SPS06: OData V4 Developer Guide, Section 2.6

When a user is dropped with the ''cascade'' option, the user and all the objects owned by the user are deleted from the database. However, the objects that are owned by other users, or on which other users have privileges, are not affected by the drop command. The privileges granted to or by the dropped user are also revoked automatically.Therefore, the objects on which other users have privileges are not dropped, and the objects owned by other users are not dropped12.

The other options are not correct because they are not the consequences of dropping a user with the ''cascade'' option. The objects on which other users have privileges are not dropped, because they are not owned by the dropped user, and they may still be needed by the other users. The objects owned by other users are not dropped, because they are not related to the dropped user, and they may have dependencies or references to other objects.Reference:

SAP HANA Platform, SAP HANA SQL and System Views Reference, SQL Reference Manual, SQL Statements, DROP USER

SAP HANA Platform, SAP HANA Administration Guide, Security, User Management, Dropping Users

Dynamic SQL allows you to construct and execute SQL statements at run time, using variables and expressions that may not be supported in SQLScript. However, it also has some drawbacks, such as:

Limited opportunities for optimization: The SQL statement is potentially recompiled every time it is executed, which may affect the performance and resource consumption. The optimizer cannot use static information, such as data types, cardinalities, or indexes, to generate an optimal execution plan. The statement may also bypass the SQL cache, which stores the results of frequently executed queries for faster retrieval.

Additional SQL execution privileges are required: The user who executes the dynamic SQL statement must have the necessary privileges to access the objects and operations referenced in the statement. This may pose a security risk, as the user may gain access to sensitive data or perform unauthorized actions. To prevent SQL injection attacks, the dynamic SQL statement should be validated and sanitized before execution.

The other options are incorrect, because:

It is possible to bind the result of a dynamic SQL statement to a SQLScript variable, using the INTO clause of the EXECUTE IMMEDIATE statement. For example,EXECUTE IMMEDIATE 'SELECT COUNT(*) FROM 'TABLE'' INTO lv_count;

It is possible to use SQLScript variables in a dynamic SQL statement, using the USING clause of the EXECUTE IMMEDIATE statement. For example,EXECUTE IMMEDIATE 'SELECT * FROM 'TABLE' WHERE 'COLUMN' = ?' USING lv_value;