Top 100 QlikView Developer Interview Questions and Answers

his comprehensive guide offers 100 QlikView Developer interview questions and answers, covering everything from basic concepts to advanced features. Whether you are preparing for an interview or brushing up on your knowledge, this list will give you insights into what to expect and how to respond effectively.

Basic QlikView Developer Questions

1. What is QlikView?

QlikView is a Business Intelligence (BI) tool that allows users to analyze and visualize data from various sources. It uses an associative data model to link data fields, enabling dynamic exploration and interactive visualizations for decision-making.

2. What is the difference between QlikView and Qlik Sense?

QlikView is more focused on guided analytics, where developers build customized dashboards for users, while Qlik Sense emphasizes self-service analytics, enabling users to create their own visualizations using a drag-and-drop interface.

3. What is a QVW file in QlikView?

A QVW file is a QlikView document that contains the data model, load scripts, charts, visualizations, and UI elements used in the QlikView application.

4. What is the associative model in QlikView?

The associative model in QlikView allows users to make selections in one data field and instantly see how it affects all other fields. This enables dynamic data exploration without predefined data paths, unlike traditional relational databases.

5. What is a list box in QlikView?

A list box in QlikView is an object that displays all the distinct values of a particular field, allowing users to make selections and filter the data within the dashboard.

6. What is a QVD file?

A QVD (QlikView Data) file is a proprietary file format used by QlikView to store data in a compressed format. QVD files are highly optimized for fast loading and processing.

7. How does QlikView handle big data?

QlikView handles large datasets using in-memory technology, which allows for fast processing. Developers can optimize performance by using QVD files, incremental loading, and data reduction techniques to handle big data efficiently.

8. What is the difference between a Table Box and a Straight Table?

A Table Box displays raw data from multiple fields and does not allow calculated expressions, while a Straight Table can include calculated measures and expressions, providing more advanced data analysis.

9. What are synthetic keys, and how do you resolve them?

Synthetic keys are automatically generated by QlikView when two or more tables share more than one common field. To resolve them, you can rename fields, use concatenation, or create link tables to avoid performance issues.

10. What is a Pivot Table in QlikView?

A Pivot Table in QlikView is a chart type that allows users to view data hierarchically, summarizing and expanding rows or columns to drill down into details.

Data Loading and Scripting

11. What is a Load Script in QlikView?

A load script in QlikView is a script written to extract, transform, and load (ETL) data from different sources into QlikView. It includes commands to connect to data sources, transform data, and define data models.

12. What are the different types of loads in QlikView?

• LOAD: Basic load command to load data from a source.
• INLINE LOAD: Load data manually by defining values in the script.
• RESIDENT LOAD: Loads data from an existing table within QlikView.
• CONCATENATE LOAD: Combines data from two or more tables with similar structures.
• QUALIFY LOAD: Adds prefixes to field names to avoid conflicts.

13. What is the difference between Inner Join and Left Join in QlikView?

• Inner Join: Returns only the records that have matching keys in both tables.
• Left Join: Returns all records from the left table and matching records from the right table. Non-matching records from the right table are excluded.

14. How do you perform incremental loading in QlikView?

Incremental loading allows you to load only new or updated data instead of reloading the entire dataset. It involves comparing the new data with existing data, typically using timestamps or unique keys.

15. What are Mapping Tables in QlikView, and how are they used?

Mapping tables in QlikView are used for lookups and transformations during data loading. They allow you to replace field values based on predefined mappings.

MAP_FIELD_NAME:
MAPPING LOAD Key, Value FROM SourceFile;

LOAD Field1, ApplyMap(‘MAP_FIELD_NAME’, Field2, ‘DefaultValue’) AS NewField;

16. What is the use of the QUALIFY statement in QlikView?

The QUALIFY statement prefixes field names with the table name to avoid field name conflicts, especially when loading multiple tables with the same field names.

17. How do you handle null values in QlikView?

Null values in QlikView can be handled by using functions like ISNULL(), NULL(), or replacing them using IF() statements to provide default values.

18. What is a Resident Load, and why is it used?

A Resident Load allows you to load data from an already loaded table within QlikView. It is useful for applying transformations or calculations to data without reloading it from the original source.

19. How can you optimize data loading in QlikView?

To optimize data loading in QlikView:

• Use QVD files for faster reloads.
• Use incremental loading for large datasets.
• Remove unused fields and tables.
• Use WHERE clauses to filter data during load.

20. What is a Master Calendar, and how do you create it?

A Master Calendar is a table in QlikView used to manage and standardize dates across different data sets. It includes fields such as year, month, day, and quarter. You can create it by generating all possible date fields from a minimum and maximum date in the dataset.

Advanced Scripting and Data Modeling

21. What are the best practices for data modeling in QlikView?

• Use star or snowflake schemas for better performance.
• Avoid synthetic keys and circular references.
• Minimize the use of calculated fields in the front-end by performing calculations in the script.
• Use QVD files for data reuse and optimized loading.

22. What is a Link Table, and when would you use it?

A Link Table is used in QlikView to resolve synthetic keys and circular references when dealing with multiple fact tables. It centralizes shared fields from different fact tables, linking them in a single table.

23. How do you create and use QVD files in QlikView?

To create a QVD file:

STORE TableName INTO FileName.qvd;

To load from a QVD:

LOAD * FROM FileName.qvd (qvd);

QVDs are used to store large datasets in a compressed format, enabling faster reloading and better performance.

24. How do you optimize the performance of a QlikView application?

• Use aggregation and pre-calculation in the load script.
• Limit data volume by loading only relevant data.
• Optimize expressions in charts by simplifying or pre-calculating them.
• Use incremental loading to reduce reload times.
• Utilize QVD files for efficient data storage and retrieval.

25. What is Circular Reference in QlikView, and how can you avoid it?

A circular reference occurs when tables are linked in a loop. To avoid it:

• Rename fields to prevent unwanted associations.
• Use link tables to break circular references.

26. What is the ApplyMap() function, and how does it work?

The ApplyMap() function allows you to perform lookups by mapping field values from a mapping table. It is commonly used for transforming or replacing field values.

MAP_FIELD:
MAPPING LOAD Key, Value FROM SourceFile;

LOAD Field1, ApplyMap(‘MAP_FIELD’, Field2, ‘DefaultValue’) AS NewField;

27. How do you handle slowly changing dimensions (SCD) in QlikView?

To handle SCD in QlikView, use techniques such as adding valid-from and valid-to dates to manage historical data or using the ApplyMap() function to manage type 1 or type 2 SCDs.

28. What are the different join types in QlikView?

• INNER JOIN: Returns matching records from both tables.
• LEFT JOIN: Returns all records from the left table and matching records from the right table.
• RIGHT JOIN: Returns all records from the right table and matching records from the left table.
• OUTER JOIN: Returns all records when there is a match in either table.

29. What are derived fields, and how do you create them in QlikView?

Derived fields are fields created from existing fields through calculations or transformations. For example:

LOAD Field1, Field2, (Field1 + Field2) AS Total;

30. How do you deal with duplicate records in QlikView?

You can remove duplicates by using the DISTINCT keyword in the load script:

LOAD DISTINCT * FROM data_source;

Set Analysis and Expressions

31. What is Set Analysis in QlikView?

Set analysis in QlikView is used to define a subset of data within an expression, allowing you to calculate results based on specific conditions, independent of user selections.

32. What is the syntax of Set Analysis?

The basic syntax of Set Analysis is:

SUM({} Field)

33. How do you exclude selections in Set Analysis?

To exclude selections, use the following syntax:

SUM({} Sales)

34. How do you calculate Year-to-Date (YTD) sales using Set Analysis?

SUM({} Sales)

35. What is the difference between 1 and $ in Set Analysis?

• 1: Ignores all user selections.
• $: Refers to the current selection set.

36. How do you create a dynamic Set Analysis expression in QlikView?

Dynamic set analysis allows you to create expressions that change based on user selections. For example, to calculate last year’s sales:

SUM({} Sales)

37. How do you use the AGGR() function in QlikView?

The AGGR() function in QlikView is used to aggregate data over a specified dimension. For example:

MAX(AGGR(SUM(Sales), Region))

This calculates the maximum sum of sales across regions.

38. What is Alternate States in QlikView, and how do you use it?

Alternate States allow different user selections in the same document without affecting each other. For example, you can compare sales for two different regions side by side by assigning charts to different states.

39. How do you calculate running totals in QlikView?

You can calculate running totals using the RangeSum() function:

RangeSum(Above(SUM(Sales), 0, RowNo()))

40. How do you handle complex calculations in QlikView expressions?

For complex calculations, use nested functions and set analysis in expressions. Pre-calculate wherever possible to reduce computation load in the front end.

Dashboard Design and Visualization

41. What are the best practices for designing QlikView dashboards?

• Keep the design simple and user-friendly.
• Use consistent colors and chart types.
• Provide clear navigation with list boxes and filters.
• Use KPIs and summary metrics for quick insights.
• Ensure the dashboard is responsive and performs well.

42. What is the role of a Container object in QlikView?

A Container object in QlikView allows developers to organize multiple charts or objects in a single space. It helps in improving dashboard layout by allowing users to switch between different charts in the same container.

43. What is the difference between a Bar Chart and a Line Chart in QlikView?

A Bar Chart is used to compare quantities across categories, while a Line Chart is used to track changes or trends over time. Choose the appropriate chart type based on the type of data and the insights you want to deliver.

44. How do you enable drill-down functionality in QlikView?

Drill-down functionality is enabled by defining drill-down groups in the Dimensions tab. This allows users to click on a high-level category and drill down into more detailed data.

45. What are cyclic groups in QlikView, and how are they used?

Cyclic groups allow users to toggle between different dimensions in a chart. This is useful when you want to analyze the same metric (e.g., sales) across different dimensions like regions, products, or time periods.

46. How do you create calculated dimensions in QlikView?

A calculated dimension is created by using an expression in the dimension definition. For example:

IF(Sales > 1000, ‘High’, ‘Low’)

47. What is a Trellis Chart, and how do you create one in QlikView?

A Trellis Chart displays small multiples of a chart based on different values of a dimension. To create a Trellis Chart, use the “Trellis” option in the Chart Properties window, enabling users to visualize comparisons across multiple categories.

48. How do you handle performance issues in dashboards?

• Simplify expressions and calculations.
• Pre-aggregate data in the load script.
• Limit the number of data points and objects in a single sheet.
• Use QVDs and incremental loads to speed up data access.

49. How do you use the Text Object in QlikView?

A Text Object allows you to display dynamic text or KPIs in your dashboard. For example:

=’Total Sales: ‘ & SUM(Sales)

50. How do you create a responsive dashboard in QlikView?

To create a responsive dashboard:

• Use well-organized sheet objects.
• Minimize clutter by using containers.
• Test the layout across different screen resolutions and adjust object sizes accordingly.

Security and Access Control

51. What is Section Access in QlikView?

Section Access is QlikView’s security feature that controls which users have access to specific data within a document. It restricts user access at the row level and sheet level.

52. How do you implement Section Access in QlikView?

Section Access is implemented using a special load script that defines user roles, access levels, and restrictions. For example:

SECTION ACCESS;
LOAD ACCESS, USERID, PASSWORD, REGION
FROM AccessControl.csv;

SECTION APPLICATION;
LOAD * FROM SalesData.csv WHERE REGION = REGION;

53. What is NTFS and DMS authentication in QlikView?

• NTFS: QlikView uses the Windows file system to manage access control, where user permissions are managed via Active Directory.
• DMS: QlikView manages access control using its own Directory Management System, allowing for more flexible, custom authentication methods.

54. How do you manage document-level security in QlikView?

Document-level security controls access to specific QlikView documents using the QlikView Management Console (QMC) or by applying Section Access in the load script.

55. How do you restrict access to certain fields for specific users in QlikView?

You can restrict access to certain fields by using the REDUCTION and OMIT keywords in the Section Access script, which defines which fields or rows each user can access.

QlikView Management and Deployment

56. What is the QlikView Management Console (QMC)?

The QlikView Management Console (QMC) is a web-based interface used by administrators to manage QlikView environments. It is used for tasks such as scheduling data reloads, managing user permissions, and distributing QlikView documents.

57. How do you schedule data reloads in QlikView?

You can schedule data reloads using the QlikView Management Console (QMC) by creating tasks that define the frequency of reloads. QlikView Publisher can also be used to automate this process.

58. What is QlikView Publisher, and how does it work?

QlikView Publisher is an add-on to QlikView Server that enables task automation, such as data reloads, document distribution, and user authentication. It ensures that QlikView documents are always up-to-date and securely distributed.

59. How do you monitor the performance of a QlikView application?

You can monitor the performance of a QlikView application using QlikView’s built-in monitoring tools, such as Session and Performance logs, or third-party monitoring tools that track memory usage, CPU load, and session activity.

60. How do you deploy a QlikView application?

To deploy a QlikView application, you need to:

1. Develop the application in QlikView Desktop.
2. Upload it to the QlikView Server using the QMC.
3. Configure user permissions and access rights.
4. Schedule reload tasks and distribute the document to users.

Troubleshooting and Debugging

61. How do you debug load script errors in QlikView?

Use QlikView’s built-in debugger to step through the load script line by line. The TRACE command can also be used to display custom messages during script execution.

62. What is the TRACE function, and how do you use it?

The TRACE function is used for debugging scripts by printing messages to the script execution window. For example:

TRACE Data loading started;

63. What are some common performance bottlenecks in QlikView, and how do you resolve them?

Common bottlenecks include large datasets, complex expressions, and too many visualizations on a single sheet. To resolve them, optimize data models, pre-aggregate data, reduce the number of calculations, and limit objects on sheets.

64. How do you troubleshoot slow dashboard performance?

• Simplify complex expressions and use pre-calculations.
• Limit the number of rows and columns in tables.
• Use aggregation in the load script.
• Ensure your data model is efficient (e.g., avoid synthetic keys).

65. How do you handle circular references in QlikView?

Circular references can be resolved by renaming fields to break unwanted links between tables or by creating link tables to manage shared keys.

Advanced QlikView Developer Topics

66. How do you implement Section Access with dynamic data reduction?

To implement dynamic data reduction, use a field in the data model that matches the user’s role or region, and restrict access based on that field using Section Access.

67. What are Alternate States, and how do they enhance analysis in QlikView?

Alternate States allow users to make independent selections within different objects on the same dashboard. This feature is useful for comparing data sets side by side without affecting the entire application.

68. How do you use QlikView Extensions?

QlikView Extensions allow developers to add custom visualizations and functionality beyond what’s available out of the box. Extensions are built using web technologies like HTML, CSS, and JavaScript and can be added to QlikView applications.

69. What is the difference between Inline Load and Resident Load?

• Inline Load: Manually loads data directly into the load script without an external file.
• Resident Load: Loads data from an already existing table within the same QlikView document.

70. How do you use triggers in QlikView?

Triggers in QlikView automate actions based on events like opening a document, making selections, or changing sheet objects. You can configure triggers to automatically refresh data, apply selections, or navigate between sheets.

QlikView Certification and Career Development

71. What certifications are available for QlikView developers?

• QlikView Business Analyst: Focuses on creating reports and visualizations.
• QlikView Data Architect: Covers data modeling, scripting, and optimization.
• QlikView System Administrator: Focuses on managing QlikView environments.

72. What are the key skills required for a QlikView developer?

• Proficiency in QlikView development and data visualization.
• Strong data modeling and ETL skills.
• Advanced scripting (including SQL and QlikView script).
• Ability to optimize performance and handle large datasets.

73. How do you transition from QlikView to Qlik Sense?

Since Qlik Sense is built on a similar architecture, transitioning involves learning Qlik Sense’s self-service features, responsive design capabilities, and modern APIs. Many QlikView developers learn Qlik Sense to enhance their BI skills.

74. What is the future of QlikView development?

While QlikView remains widely used for guided analytics, Qlik is focusing on Qlik Sense for future developments. However, QlikView still has a strong presence in businesses that rely on its legacy applications.

Real-World Scenarios and Case Studies

75. How do you manage a QlikView application with multiple fact tables?

Managing multiple fact tables often requires using link tables to centralize shared dimensions and avoid synthetic keys or circular references.

76. How do you design a QlikView dashboard for sales analysis?

To design a sales dashboard:

1. Load and model sales data (e.g., orders, customers, products).
2. Create KPIs like total sales, average order value, and customer count.
3. Use bar charts, line charts, and pivot tables to visualize sales trends by region, product, and time.
4. Implement filters for dynamic drill-down.

77. How do you handle real-time data in QlikView?

QlikView is not designed for real-time data but can simulate near real-time analysis by using frequent data reloads or integrating with real-time data sources through APIs.

78. How do you handle security in a multi-user QlikView environment?

In multi-user environments, implement row-level security using Section Access, manage user roles with Active Directory or DMS, and control document access via the QlikView Management Console (QMC).

79. How do you migrate a QlikView application to Qlik Sense?

Qlik provides migration tools to assist with transitioning applications from QlikView to Qlik Sense. Key steps include exporting data models, recreating visualizations, and leveraging Qlik Sense’s advanced features like responsive design and self-service analytics.

80. How do you integrate QlikView with other BI tools?

QlikView can be integrated with other BI tools like Tableau or Power BI via APIs, data connectors, or by exporting data in formats like CSV or Excel for cross-platform analysis.

Advanced Real-World Scenarios

81. How do you implement a Master Calendar in QlikView?

A Master Calendar is created by loading the minimum and maximum dates from your dataset and generating all possible dates. Then, you define fields like year, month, and quarter for use in visualizations.

82. How do you handle multi-language dashboards in QlikView?

Multi-language dashboards can be created by storing translations in a table and using ApplyMap() or conditional expressions to display the correct language based on user selections.

83. How do you handle seasonality analysis in QlikView?

For seasonality analysis, create date-based filters and charts that display trends over time. Use set analysis to compare data across different time periods, such as year-over-year or month-over-month.

84. How do you monitor data reloads and manage failures?

Monitor data reloads via QMC, set up alerts for reload failures, and use error handling in the script (e.g., SET ErrorMode = 0;) to catch and log errors during the reload process.

85. How do you visualize KPIs in a QlikView dashboard?

KPIs can be visualized using Text Objects, Gauge Charts, or specialized KPI widgets. Use expressions like SUM(Sales) or AVG(Profit) to calculate metrics, and color-code them based on thresholds (e.g., green for target achieved, red for underperformance).

86. How do you implement dynamic charts in QlikView?

Dynamic charts allow users to switch between different chart types or dimensions. This can be implemented using variables and input boxes or by creating cyclic groups.

87. How do you optimize large QlikView applications?

To optimize large applications:

• Use QVDs to pre-load and store data.
• Minimize data by using WHERE clauses during load.
• Aggregate data in the script instead of calculating it in the front-end.
• Limit the number of visualizations and data points on a single sheet.

88. How do you handle time series data in QlikView?

For time series data, create a Master Calendar and use date fields like year, quarter, and month. Use line charts to track trends over time and apply set analysis for year-over-year comparisons.

89. How do you handle cross-tab reports in QlikView?

Cross-tab reports can be created using Pivot Tables, which allow you to drag dimensions into rows and columns for a multi-dimensional view of the data.

90. How do you compare performance across different regions in QlikView?

Use bar charts, line charts, or maps to compare sales, revenue, or other KPIs across regions. Implement drill-down functionality to allow users to explore performance at different geographic levels.

Miscellaneous and Industry-Specific Questions

91. How do you handle healthcare data in QlikView?

For healthcare data, use data models that handle patient records, visits, and outcomes. Build dashboards that display patient metrics, appointment trends, and health outcomes. Implement privacy controls using Section Access.

92. How do you visualize marketing campaign performance in QlikView?

Visualize marketing performance by tracking KPIs like conversions, leads, and ROI. Use bar charts, funnel charts, and trend lines to monitor campaign performance over time.

93. How do you analyze customer segmentation in QlikView?

Customer segmentation can be visualized using pivot tables and charts that group customers by demographic variables, purchasing behavior, or geography. Use set analysis to create dynamic segments based on selections.

94. How do you perform financial forecasting in QlikView?

Financial forecasting in QlikView can be done using historical data and trend analysis. Use line charts to display revenue trends and apply set analysis to simulate different forecasting scenarios.

95. How do you handle supply chain data in QlikView?

For supply chain data, model the data to track shipments, inventory levels, and supplier performance. Build dashboards that display KPIs like delivery times, order accuracy, and stock levels.

96. How do you use QlikView in the retail industry?

In retail, QlikView can be used to track sales, inventory, and customer data. Build dashboards that display sales trends, product performance, and customer segmentation for targeted marketing.

97. How do you integrate QlikView with CRM systems?

QlikView can integrate with CRM systems like Salesforce or HubSpot via connectors or APIs. This allows you to analyze customer data, sales activities, and marketing performance in QlikView dashboards.

98. How do you handle GDPR compliance in QlikView?

Ensure GDPR compliance by anonymizing personal data, limiting access to sensitive information using Section Access, and providing audit logs for data usage.

99. How do you create financial statements in QlikView?

Financial statements such as balance sheets and income statements can be created using pivot tables and calculated measures. Use set analysis to calculate metrics like net income and gross profit.

100. What are the challenges faced by QlikView developers, and how do you overcome them?

Common challenges include handling large datasets, optimizing dashboard performance, and managing evolving business requirements. Overcome these challenges by optimizing data models, using QVD files, simplifying expressions, and collaborating closely with stakeholders to ensure that business needs are met.

Conclusion

These top 100 QlikView developer interview questions and answers cover everything from basic concepts to advanced techniques, helping you prepare for your next interview. With these insights, you’ll be well-equipped to showcase your knowledge and problem-solving skills, making a strong impression as a QlikView developer.