Top 25 Cognos Interview Questions and Answers in 2024

Editorial Team


When it comes to getting ready for a Cognos interview, understanding what most interviewers ask is the best way to prepare. Understanding Cognos interview questions and answers will boost your chances of getting hired. Here are 25 Cognos interview questions and answers to help improve your interview experience.

1. What Is Cognos?

Cognos refers to a business intelligence performance tool designed for IBM that enables non-technical and technical employees in any given company to extract, analyze, and establish interactive dashboards that allow the company to make relevant integral decisions. This tool incorporates multiple products, which allow easy communication with various third parties. The highly interactive nature of Cognos also makes it an ideal method of establishing user-friendly dashboards as well as reports for companies.

2. What Are The Key Features Of Cognos?

Cognos tool comes with multiple features. To begin with, automated transfer calculation of actual period values, and distribution entry that creates and delivers personalized reports in the required formats. This automatically keeps stakeholders up-to-date. It can enter action data as well as status for metrics in red status. It comes with an automated and highly flexible security permissions management at any level. It also comes with the capacity to construct interactive impact diagrams in each scorecard.

3. How Does Cognos Make Work Easier?

Cognos is used for analytical tasks to take key business decisions at the right time, which is necessary for survival in the ever-challenging market. It has made working easier for organizations and enterprises as it is powered by artificial intelligence and machine learning, which allows it to make future predictions and establish intelligent dashboards. It utilizes pattern detection property to disclose hidden patterns in the data that could not be expected or heard under normal circumstances. It also comes with vital features such as the ability to create interactive dashboards in various formats, catering to varied business needs. Another way Cognos has made working easier is by using natural-language powered Al, which helps users to obtain intelligent responses to the queries they pose. While manual tasks take time and effort, Cognos eliminates manual interventions, through its built-in intelligence system, by automating the data preparation process.

4. What Are The Advantages Of Cognos?

Cognos provides a crucial tool in key decision-making in any business enterprise. It comes with multiple advantages. To begin with, data preparation. Files in different formats such as spreadsheets or CSV can be accessed and uploaded with ease. With the aid of its intelligent system that utilizes natural language, it finds relevant data sources and automates the combination process of different data sources. The second advantage is data exploration. Cognos visualizes and reports data in a professional manner. Besides, its intelligent features enable it to plot the precise chart for a specific business problem. Another advantage is data sharing. Once data is prepared and evaluated, it can be shared in a cloud or over various platforms. It also allows users to report any subscriptions.

5. Does Using Cognos Require Any Skills?

Even though Cognos is a tool that requires no technical pre-requisites to master, you must have proper data intuition and be knowledgeable enough to ensure that precise data is utilized to make key business decisions.

6. What Are The Differences Between Tableau Desktop And Cognos?

The major difference between a tableau desktop and Cognos is their compatibility. While tableau provides platform compatibility with web-based, windows, and android devices, Cognos is compatible with Linux, windows, and web-based platforms. Tableau functions better compared to Cognos in data modeling and data transformation. Cognos, on the other hand, functions better in ad-hoc reporting as well as standard reporting. Cognos also works better in access control and security functionalities compared to the tableau desktop which provides less security and access control functionalities.

7. What Is Cognos Dynamic Cube?

Cognos dynamic cube is the in-built memory that works to directly load data from well-structured relational data management sources. These cubes are an extension of IBM Cognos Dynamic Query, which leverages significant in-memory data assets and aggregate awareness for it to attain higher interactive analysis as well as report compared to terabytes of warehouse data.

8. Describe The Elements Of Cognos Dynamic Cube

The Cognos dynamic cube comprises three integral elements. The first element is the Cognos cube designer which is the modeling tool, comparable to the transformer. Next is the Cognos dynamic cube server which contains details about the Cognos dynamic cube. The third element is the aggregate advisor which is launched from the Cognos dynamic query analyzer.

9. When Do You Use Cognos Dynamic Cube?

Cognos dynamic cube was designed to address the challenges posed by high-performance as well as low latency interactive analysis against terabytes of data. They are often utilized when the data volume supersedes terabytes. Use Cognos dynamic cube when you require low latency and high performance, as well as high volume data analysis and reporting. They are used only for snowflake or star modeled data warehouses to provide in-memory relational OLAP functionality. Additionally, you can use dynamic cubes in Cognos when a database comprises more than twenty-five million table rows.

10. Explain The Cognos Cube Designer Modelling Workflow

Cognos cube designer modeling involves a series of crucial steps. First, select the database schema. Import the needed metadata. Once the required metadata is imported, define the dimensions and measurements, creating the dynamic cube. Auto-generate the dynamic cube using primary-foreign integral relationships to populate dimensions. Once that is done, model the cube manually and then deploy it to the BI server with a publishing option. An option that is selected must be performed manually in the Cognos connection.

11. How Do You Create Security Features For Cognos Cubes?

To create security features for cubes, use the user class views as well as dimension views. Dimension views are designed to help hide certain data from the cube depending on the type of view you are using. You can use the user class views on the cubes to make that data available for a particular group or role. You can as well use password protection as another method of creating security for the cubes.  In short, create security features for Cognos cubes by stopping or starting the cube, monitoring the cube, managing the cache memory, and last but not least, scheduling to refresh the cache memory management.

12. Explain About Aggregate Advisor

An aggregate advisor is a performance optimization tool that is part of your dynamic query analyzer. The key function of the aggregate advisor is to suggest in-memory aggregate, database aggregate tables, or both. It not only makes use of your cube’s statistics and model; it also makes use of your workload’s log files that are created from the executed reports. The dynamic cube is expected to be published in the content store, where it can be successfully started and the reports and analysis return accurate results. After restarting a cube, the aggregates execute the required SQL statements to retrieve the summarized values, placing them in aggregate cache for use during query processing. The aggregate advisor should be run ideally during off-peak, or non-critical business hours.

13. Briefly Explain Aggregate Cache

Cognos dynamic cubes support two categories of pre-computed aggregate values; those that are stored in database tables (in-database aggregate) and those that are stored in an in-memory aggregate cache. Aggregate advisor suggests a collection of in-memory aggregate which doesn’t require the inclusion of DBA. Recommendations are thereby stored in the content manager where they take effect the next time your cube is started. The aggregate cache’s size is specified within the properties of a dynamic cube.

14. What Is Aggregate Cache Size?

Aggregate cache size ideally only uses sufficient memory required to hold the specified aggregates. For instance, if 100 MB can hold the aggregates for particular sales, the aggregate cache size is supposed to be set at 1 GB, meaning only 100 MB of memory will be used. Suppose the underlying fact table grows over time, the aggregates are allowed to increase to the recommended maximum of 1 GB. The aggregate cache should not use more than 30 GB.

15. Explain What You Understand By Model Durability

In order to achieve a durable model, some criteria must be met. There is a designed language designed for the model that is not similar to the locales that users can choose from. Typically, the design language is English. The design language name of all query subjects, namespaces, and query items that are published in a package, must never be changed at any point after the initial publication. However, the other language names can be changed as required. The structure of the published query subject, namespace, query items, query subjects, shortcuts, dimensions, etc., on the package, must never change over time. This is because the structure is typically stored in a defined specification along with the name of the design language. Once these standards are met, you have what is considered to be a durable model.

16. What Changes Can You Make To Make A Model Durable?

There are a couple of changes that can be made if a model is not durable. For starters, if the model doesn’t have a design language already, then, add the essential design language to your model, adding it to the design languages of each package depending on the model. Thereafter save and close the model. You can also open the model .xml file, using a text editor or an XML, and change the value of en (located near the top of the file) to en-zw. To make an IBM Cognos 8.4.1 a durable model, insert a blank line into your model.xml file below the modified element, adding true to your new blank line. To make an IBM Cognos 8.4.1 a durable model, insert a blank line into your model.xml file below the modified element, adding true to your new blank line. For IBM Cognos 10, set your project level property, using design locale for your reference ID, to a value of true.

17. What Is Framework Manager?

Framework manager is a kind tool that enables users to ensure that data sources are available for different Cognos suites. It also allows you to add additional logic information. A framework model comprises logical and vital information, within the environment of logical Cognos architecture, which is required for Cognos tools during software development.

18. What Are The Different Types Of Securities That Can Be Applied In Framework Manager?

The framework manager security comes in handy in restricting the access of metadata and controlling unauthorized access to your application. Various types of security can be applied in the framework manager. To begin with, the data security. Through the help of data security, you can create security filters and apply security procedures to the query subject. Data security is a type of data filter that controls data that is intended to be used during reporting time. The second type of security that you can apply in framework manager is object security. Here you may directly secure the object by denying users access to your data objects, enabling users to access the proper data, and making it invisible from all users. The third security type is package security. Here, users can basically apply security to their packages and restrict who can access those packages.

19. Describe IBM Predictive Maintenance And Quality

IBM predictive maintenance and Quality is a tool that can be used to monitor, analyze, and report information gathered from your devices. It can also generate recommendations for actions, making it a vital tool that aids key decision-making. Predictive maintenance and quality, as an integrated solution, can also be used to perform multiple other tasks. To begin with, it can predict the malfunction of an instrumented asset, enabling you to combat costly unexpected downtime. Predicting future failures can also help you make adjustments to your routine predictive maintenance tasks and schedules to minimize downtimes and reduce repair costs. IBM predictive maintenance and quality not only checks maintenance logs to evaluate the most effective maintenance cycles and repair procedures, but it also identifies the root cause of system failure faster, allowing you to take corrective actions. It identifies reliability and quality issues definitively and in a timely manner.

20. How Do You Create Regular Dimensions?

Regular dimensions are generated from database query subjects or model query subjects. The first step in creating a regular dimension is by defining hierarchies to define drill paths and organize levels. You may define multiple hierarchies in one dimension. Also define business keys, levels, and caption. Using “Convert to Regular Dimension” or “Merge in New Regular Dimension” capabilities, the dimension will be generated automatically depending on the query subject definition.

21. What Is Orchestration In IBM Predictive Maintenance And Quality?

Orchestration refers to the process that ties activities in your IBM predictive maintenance and quality together. There are two key types of orchestration message flows and generic batch orchestration. In message flows, orchestration is accomplished with message flows within the IBM integration bus. Generic batch orchestration allows abilities to run a scheduler flow, invoking any IBM SPSS batch job by collecting inputs from a configurable XML file rather than creating a separate message flow for a particular use.

22. How Do You Create Measure Dimension?

Measure dimension begins by collecting facts. It is created using convert to measure dimension or dimension definition dialog capabilities. Create calculations or add existing measures then define scope relationships. Once this is done, dictate the level at which your measurements are available for reporting. The framework manager will detect the scope relationship using the underlying joined paths between fact query subject and query subjects. You may define and review scope relationships in the dimension map.

23. What Are Determinants?

Determinants refer to the advanced features introduced in Cognos that provide control over granularity during data aggregation. It is used to make sure that repeating data aggregates accurately and provides index information in a database. The framework manager uses determinants to determine default hierarchy levels when auto-generating the regular dimensions from your data query subjects.

24. When Should You Use Determinants?

Use determinants when your dimensions connect to the fact tables at granularity levels that consist of repeating keys. Additionally, use determinants when it is necessary to perform aggregate procedures on an attribute or key that is repeated to avoid creating a distinct clause on different keys.

25. What Is The Advantage Of Using Shortcuts?

There are two different types of shortcuts available in Cognos; local and global. Global shortcuts are typically used for the global repository, whereas local shortcuts are used to maintain the local repository. The major advantage of using these shortcuts is the ability to rescue an object rather than to create multiple data objects.


Understanding these Cognos interview questions and answers will also help to evaluate your knowledge and skills more effectively. That way, you can improve on your weak areas and build your confidence. Ensure to take a look at the company’s website to familiarize yourself with basic questions about your potential employer. Also, be sure to dress decently and arrive early for the interview.