C_HAMOD_2404 SAP Certified Associate - Data Engineer - SAP HANA Question and Answers

To verify if pruning occurs with a referential join in a calculation view:

Enable the Debug Query Mode (C):This mode helps identify which columns from the source tables are being utilized in the query execution.

Performance Analysis Mode (D):Observing which columns are mapped and analyzed in this mode indicates the impact of referential joins and whether data sources are effectively pruned.

Parameter mapping in SAP HANA calculation views serves several purposes:

To push down filters to the lowest level calculation views:By mapping input parameters from a higher-level calculation view to those in underlying views, filters applied at the top level are propagated down to the base views. This ensures that data is filtered as early as possible in the data processing pipeline, reducing the volume of data transferred and processed, thereby enhancing performance.

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To pass variable values to external value help views:When using external views to provide value help (i.e., lists of possible values) for variables or input parameters, parameter mapping allows the values entered by the user to be passed to these external views. This enables dynamic and context-sensitive value help, improving the user experience by presenting relevant options based on prior selections.

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Options B and D are not correct in this context:

To convert the data types of input parameters:Parameter mapping does not inherently perform data type conversion. Data type consistency must be ensured when defining input parameters and their mappings.

To assign variables to one or more attributes:Parameter mapping is not used to assign variables to attributes; rather, it links input parameters and variables between different calculation views or external sources.

If the account number is not masked in calculation view A, it indicates that masking was not defined in calculation view A. Masking rules must be explicitly defined at every level where data is exposed, as they are not inherited from underlying views.

TheOPTIMIZED linked databasefeature improves access to remote objects:

A. The metadata of remote tables is cached on the target system: This reduces the overhead of fetching metadata repeatedly.

C. The source and target system must be SAP HANA: This feature is designed specifically for SAP HANA systems for seamless integration.

Hidden virtual tables (B) are not automatically created, and explicit database names (D) are not required.

EnablingDebug Query modein a calculation view allows you to:

Identify data sources that are not accessed by a query: This helps in debugging and optimizing the calculation view by showing which nodes or sources are unnecessary for a specific query.

When creating a calculation view that accesses a table in an external schema:

A. Synonym: Synonyms act as aliases to access external schema objects. They are required to integrate external tables into the calculation view.

D. Authorization: You need appropriate schema authorizations to access the external table through the synonym.

A remote source (B) is used for accessing remote systems, and an SQL view (C) is not necessary for this scenario.

The "Ignore multiple outputs for filters" property in a calculation view ensures that filters are applied consistently and correctly at thelowest node. This setting forces filters to be applied as early as possible in the data flow, ensuring that redundant or incorrect data processing does not occur at higher nodes. This improves performance and maintains the integrity of the filter logic.

The procedure should have the value DEFINER for the security mode (A):This ensures the procedure executes with the privileges of its creator rather than the calling user, which is critical for security and consistent behavior in a dynamic analytic privilege.

The procedure should be defined as read-only (D):Procedures used in dynamic analytic privileges must not modify data; they should only perform read operations to ensure data integrity and prevent unintended changes.

Options B and C are incorrect as input parameters for user IDs and return tables with allowed values are typically associated with table functions rather than procedures in this context.

AnInput Parameteris used in calculated columns to process dynamic values within expressions. Input parameters can be defined to accept runtime values or calculations, enabling dynamic data manipulation within a calculation view. Variables, in contrast, are primarily used for filtering.

Best practices for writing SQLScript in calculation views include:

A. Break up large statements by using variables: This makes the script easier to read, maintain, and debug.

D. Choose declarative language instead of imperative language: Declarative SQL is more efficient and optimized for database processing in SAP HANA.

Dynamic SQL (B) and control flow logic (C) are discouraged due to potential performance and maintenance issues.

Nesting flowgraphs provides several advantages:

A. To reduce flowgraph maintenance: Nested flowgraphs promote reusability, reducing redundancy and simplifying maintenance.

C. To improve flowgraph performance: By nesting, you can modularize complex processes, optimize individual components, and enhance overall performance.

Additional node types (B) or simultaneous flowgraph execution (D) are not specific benefits of nesting.

To create a star schema using a calculation view with measures based on columns from two transaction tables:

Combine the transaction tables using a join node in a CUBE calculation view:The join node merges the transaction tables into a unified fact table.

Use a star join node to join the DIMENSIONS to the resulting fact table:The star join node integrates the attributes from the DIMENSION views with the measures in the fact table, completing the star schema design.

This approach adheres to best practices for building efficient star schemas in SAP HANA.(Reference: SAP HANA Star Schema Modeling Guide)

TheTransparent Filterproperty is used in SAP HANA to allow filter push-down in stacked calculation views. This ensures that filters applied to one layer of the view are propagated to underlying views, enhancing performance by reducing the volume of data processed at higher levels.(Reference: SAP HANA Transparent Filter Guide)

ï‚·The block must start with a node that defines a table as a data source (C):Parallelization blocks are designed to work with table-based nodes as starting points for splitting workloads.

ï‚·Only one block can be defined across a stack of calculation views (D):This restriction ensures consistency and avoids conflicts during parallel execution.

In a flowgraph, the data source node supports various types of objects for flexibility in data integration:

A. Virtual table: Enables access to remote data sources via Smart Data Access (SDA).

B. Calculation view: Allows using pre-aggregated or calculated data as a source.

D. Synonym: Serves as an alias for database objects, simplifying access to objects across schemas.

Procedures (C) and table functions (E) are not directly used as data sources in flowgraphs.

If Table B is not pruned in a referential join, the possible issues could be:

C. The Keep flag is activated for the Customer column: This prevents pruning by forcing the inclusion of the column in query execution.

D. Integrity constraint is set to RIGHT: This setting implies that Table B data must always be considered in the join, disabling pruning.

Pruning depends on join conditions and flags; ensuring no unnecessary constraints is essential for proper optimization.

The simplest approach to create the required output from the provided table is to implement aUnion Nodein the calculation view and map each year as a separate column. This method efficiently aligns data across different columns without needing extensive calculations or additional filter expressions. It provides a structured output while minimizing complexity in the model.(Reference: SAP HANA Calculation View Modeling)

To view data for the United States when querying aCUBE calculation view, the user must have:

SELECT privilege on the CUBE calculation view: To execute queries on the view.

Analytic Privilege (Country United States) on the DIMENSION calculation view: This restricts access based on the country dimension to only "United States" data.

Analytic privileges must be defined appropriately on both views to enforce the required data access.