Denodo provides enterprises with a data virtualisation platform to theoretically combine information from disparate sources without physically moving it between systems.

This explains the rising need for knowledgeable Denodo personnel as demand for data virtualisation solutions increases.

Here we have provided a selection of the most frequently-asked Denodo Interview Questions that should help any applicant prepare with confidence for an interview, no matter their level of experience or knowledge.

No matter whether you are just getting into data virtualisation or already an expert looking to broaden their skillset, let’s examine some of the frequently-asked questions about Denodo during interviews.

1. What is Denodo 8, and what are its capabilities?

Denodo 8 is a data virtualisation platform that enables real-time access to disparate data sources and provides new data views from multiple sources.

Its capabilities include creating new data views from disparate data sources, optimising query performance, and enabling end users to access and leverage Denodo views in their reports and applications.

2. What are the focus areas of Denodo 8’s data virtualisation capabilities?

Denodo 8’s data virtualisation capabilities focus on creating new data views from multiple disparate data sources, optimising query performance, and enabling end users to access and leverage Denodo views in their reports and applications.

3. What are the benefits of enterprise data virtualisation?

Enterprise data virtualisation provides real-time access to disparate data sources, including traditional relational databases, SaaS applications, Hadoop, and web services. It also provides a data abstraction layer for business intelligence and application developers.

 4. How does Denodo’s data virtualisation server provide connectivity for applications to access data from any data source?

Denodo’s data virtualisation server provides connectivity for applications to access data from any data source by creating a data abstraction layer that allows users to query data from multiple sources as if they were a single data source.

5. What is the difference between virtualisation and traditional data integration approaches?

Data virtualisation provides a data abstraction layer that allows users to query data from multiple sources as if they were a single data source. In contrast, traditional data integration approaches require manual data extraction and manipulation.

6. What are the drawbacks of traditional data integration tools?

Traditional data integration tools typically create an ETL job or have a power user manually extract data sets from each source, which can be time-consuming and prone to errors.

7. How does Denodo 8 offer a different approach to solving many data integration problems?

Denodo 8 offers a data virtualisation approach that enables users to query data from multiple sources as if they were a single data source without manual data extraction and manipulation.

8. What are the benefits of using Denodo 8?

The benefits of using Denodo 8 include real-time access to data where it resides, reducing the need for extracting and storing data, and a single sign-on solution for all tools.

9. How does Denodo determine the optimal execution plan for retrieving data?

Denodo determines the optimal execution plan for retrieving data from sources in real time, using metadata and query performance analysis.

10. What are the two environments in Denodo 8?

The two environments in Denodo 8 are the Denodo development and user environments.

11. What is the integrated demo in Denodo 8?

The integrated demo in Denodo 8 has different layers, including the connectivity layer. It allows real-time access to data where it resides, reducing the need for extracting and storing data.

The Denodo optimiser is a cost-based tool that determines the most optimal means to retrieve data from source systems in real-time when consuming applications queried to it. The optimiser uses inputs such as the incoming SQL statement, metadata on source tables, and source capabilities of the underlying systems.

13. What is the naive strategy for retrieving data?

The naive strategy for retrieving data involves issuing a select star from sales and a select star from the customer, moving all data over the network, and then joining and aggregating the data.

14. How does the Denodo optimiser choose the best execution plan?

The Denodo optimiser chooses the best execution plan based on the incoming SQL statement, metadata on source tables, and source capabilities of the underlying systems.

It incorporates all this data into its algorithm and assigns a cost to each potential execution plan, choosing the program with the lowest price.

15. How does Denodo see customer I D as the primary key in the customer table and the column used to join the sales table to the customer table?

Denodo sees customer I D as the primary key in the customer table and the column used to join the sales table to the customer table.

16. How does Denodo minimise data movement?

To minimise data movement, the sales data is aggregated at the customer ID level, reducing the number of rows returned from the sales database to 2 million.

17. What is the cost-based optimiser?

The cost-based optimiser affects the view created.

18. What does the execution trace show?

The execution trace shows the optimisations applied, time spent; total rows returned, and execution time.

19. What is the query made up of?

The query is made up of three separate gets to different data sources.

20. How is the aggregation pushdown applied to the query passed down to Presto?

The aggregation pushdown is applied to the query passed down to Presto, resulting in the aggregation being executed outside Denodo and returning the result sets.

21. What happens after testing the query and confirming the optimiser’s plan?

BI developers make the view available after testing the query and confirming the optimiser’s plan.

22. What is the Denodo catalogue?

The Denodo catalogue provides a single point of access for all Denodo assets.

23. What is view metadata?

View metadata is indexed in the repository, allowing users to search by view name, column name, or description.

The platform control centre is where you can start the various components of the Denodo platform.

25. What does the administration tool do?

The administration tool is used to configure data source connections, define virtual views, and publish them to consuming applications.

26. What is the database management page?

The database management page allows you to manage your virtual databases.

27. What is the concept of folders in Denodo Express?

Denodo Express uses the concept of folders, similar to Windows or Linux, to organise your work.

28. How do you create a new folder in Denodo Express?

To create a new folder in Denodo Express, right-click the database name, select new, and then folder from the drop-down menus.

Before ending this blog, let’s test your skills by going through the MCQ’s below.

29. What is Denodo?

a) Tool for analysing data from multiple sources

b) Enterprise data warehousing solution

c) Type of data integration tool

d) A tool for optimising database queries

 30. What does Denodo offer that traditional data integration tools do not?

a) Real-time access to data from multiple sources

b) A data abstraction layer for business intelligence and application developers

c) Solution for data quality issues

d) Feature for predicting future trends based on historical data

31. How does Denodo work to create a marketing view using a C R M data source?

a) Imports metadata for each object and exports them to the destination system

b) Establishes physical connections to data sources, imports metadata and creates base views

c) Creates an ETL job or manually extracts data sets from each source

d) Determines the optimal execution plan for retrieving data from sources in real-time

32. What does the Denodo optimiser do?

a) Assigns a priority to each view based on business value

b) Uses cost-based optimisation to determine the most optimal means to retrieve data from source systems in real time

c) Determines the optimal execution plan for retrieving data from sources in real-time

d) It determines the best data storage method for each type of data

 33. How does the Denodo server aid in data integration?

a) As a query processing engine

b) Acts as a data coordinator, allowing for real-time access to data where it resides

c) Performs data quality checks and standardisation

d) Applies complex data transformations

Denodo interview questions addressed a broad array of essential subjects for those hoping to work with this powerful data virtualisation platform.

These questions provided an in-depth knowledge of Denodo from its core fundamentals to more intricate features and functionalities.

Hopeful this blog has provided you with insight and tools needed to navigate Denodo successfully and prepare you for an interview in the near future.

Best wishes with all of your future ventures!