Basic QlikView Interview Questions
1. What are the different services of the QlikView Server Environment?
QlikView Server is a software platform that is used to publish and distribute QlikView documents to users within an organization. It provides a range of services that are designed to support the development, deployment, and management of QlikView applications.
Here are some of the key services that are provided by QlikView Server:
- QlikView Management Console (QMC): This is a web-based interface that is used to manage and monitor the QlikView Server environment. It provides tools for managing users, licenses, security, and other aspects of the QlikView Server environment.
- QlikView Distribution Service (QDS): This service is responsible for distributing QlikView documents to users within the organization. It can be configured to distribute documents via email, file share, or other methods.
- QlikView Management API (QMA): This is a set of APIs that can be used to programmatically manage and monitor the QlikView Server environment.
- QlikView Web Server (QVWS): This service provides access to QlikView documents via a web browser. It enables users to view and interact with QlikView documents from any device that has a web browser.
- QlikView Server Engine (QSE): This service is responsible for executing the QlikView script and loading data into the QlikView document. It is also responsible for handling user interactions with the document, such as selection and filtering.
- QlikView Publisher (QVP): This service is used to automate the publishing and distribution of QlikView documents. It can be configured to publish documents on a schedule, or in response to specific events.
These are just a few of the key services that are provided by QlikView Server. There are many other services and features available, depending on the version and configuration of QlikView Server.
2. Explain join and its types
In QlikView, a join is a way to combine data from multiple sources into a single table or data model. There are several types of joins that can be used in QlikView, each with its own set of characteristics and limitations.
Here are some of the key types of joins that are available in QlikView:
- Inner Join: An inner join combines rows from two or more tables based on a common field or set of fields. Only rows that have matching values in the common field(s) will be included in the resulting table.
- Left Outer Join: A left outer join combines rows from two or more tables, but includes all rows from the left (or “outer”) table, even if there are no matching rows in the right (or “inner”) table.
- Right Outer Join: A right outer join is similar to a left outer join, but it includes all rows from the right (or “outer”) table, even if there are no matching rows in the left (or “inner”) table.
- Full Outer Join: A full outer join combines rows from two or more tables, and includes all rows from both tables, regardless of whether there are matching rows in the other table.
- Cross Join: A cross join combines every row in one table with every row in another table, resulting in a Cartesian product.
Each of these join types has its own use cases and can be useful in different situations. It is important to understand the differences between them and choose the appropriate type of join based on the needs of your analysis.
3. What is the difference between Keep and Join?
In QlikView, the KEEP and JOIN functions are used to specify how data from different tables should be combined when they are loaded into the QlikView document.
The KEEP function is used to specify that data from two or more tables should be combined by keeping all of the values from one table and only matching values from the other table. This results in a table with all of the rows from the first table, and only the matching rows from the second table.
The JOIN function is used to specify that data from two or more tables should be combined by matching values in one or more common fields. This results in a table with all of the rows from both tables, with NULL values for fields that do not have matching values in the other table.
For example, consider the following two tables:
If we use the KEEP function to combine these tables, the resulting table would be:
If we use the JOIN function to combine these tables, the resulting table would be:
In general, the KEEP function is used when you want to keep all of the values from one table and only include matching values from the other table, while the JOIN function is used when you want to include all values from both tables, with NULL values for fields that do not have matching values.
4. What is the difference between the Let and Set options in QlikView?
- Let: It assigns a variable to a value after assessing the expression.
- Set: It assigns a variable to a value without assessing the expression.
5. What is Fact Constellation Schema?
Fact Constellation Schema is a collection of multiple facts tables sharing common dimension tables. It is made up of several star schemas and hence is also called galaxy schema.
6. What are the main features of Qlikview?
QlikView features are as follows
- Data visualization
- Dynamic BI Ecosystem
- Searching across all data
- Secure, real-time collaboration
- Interacting with dynamic apps, dashboards, and analytics
7. How can you bring data into QV and handle early arriving facts?
By using ODBC, OLEDB, or SAP connectors as a data connection, we can load data using the Select statement.
8. What is the use of Comparative Analysis in the Qlikview Developer Platform?
By using the Comparative Analysis option, users can quickly gain new insights to analyze their information in Qlikview.
9. In Qlikview, what is the use of an optimized load?
QVD files can be read in two modes- the standard and the optimized model. The optimized load is a faster process and is preferable for large sets of data.
10. Is it possible to load web files into QlikView? If so, how?
Yes, it is possible to load web files into QlikView. It is done through the Script Editor.
11. What is Inline data? How can we load Inline into QlikView?
Inline data is created on the spot and to load inline data in QlikView we need to open the Script Editor and then select the Insert option. After that, select Load Statement followed by Load from Inline.
12. What are Incremental load and Resident load?
Qlikview Incremental load is used for loading new or changed records from the database, whereas resident load is a part of loading data which already present in the Qlikview application.
13. What are delimited files and why are they called CSV files?
Delimited files are text files in which data fields and data values are separated by commas, semicolons, and tabs, and that is why they are also called Comma Separated Values files. These files are saved with a .csv extension.
14. What are Sheets in QlikView?
A Sheet divides a QlikView document into multiple sections. Every document will have at least one sheet in it, if needed, we can add more from the Sheet Properties option.
15. In how many ways can the Script Editor be invoked?
Script Editor can be invoked in two ways- either by the shortcut keys Ctrl+E or by the icon for Edit Script.
16. What is a Dashboard?
A dashboard is a QlikView document that displays values from many fields simultaneously and makes the analysis process easier.
17. What is buffer load, and why is it significant?
A buffer load is used to create a file using a buffer prefix in Qlikview’s memory for future use.
18. How many types of charts are used in QlikView?
The following are the types of charts used in QlikView
- Bar chart
- Mekko Chart
- Grid chart
- Funnel chart
- Line chart
- Gauge chart
- Combo Chart
- Scatter Chart
- Radar chart
- Block chart
- Straight table chart
- Pie chart
- Pivot table chart
19. What is a synthetic key, and what is its importance?
The synthetic key is created to avoid confusion when two rows of the table are the same. In QlikView, automatically, this scenario is detected, and a synthetic key is created to make the process faster.
20. What does the Auto-Generated function do in QlikView?
The auto-Generated function automatically generates the numbers between the given range.
21. What are the parameters needed by a crosstable Wizard to form a cross table?
A total of three fields are required to create a cross table, and they are as follows:
- Attribute field
- Data field
- Qualifier field
22. What are the advantages and disadvantages of QlikView?
- Data Sharing
- Data interpretation and analysis
- Self-service tool
- Low Maintenance
- Data security
- Direct and indirect search
- Inefficient real-time data analysis
- Less RAM limit
23. What is the difference between dimensional and relational modeling?
The main difference between the entity-relationship model and dimensional model is-
In the ER model, a table can have foreign keys in multiple tables that lead to circular references. In a dimensional model, a fact table contains all necessary measures surrounded by dimensional tables.
24. What is a circular reference, and how to avoid it?
In QlikView, tables get automatically connected to each other based on some key references. This process leads to the formation of unwanted structures called circular references. It is a condition when there exist two or more association paths among three or more tables. This condition can be corrected in the following ways-
- Renaming data fields
- Creating a link table
- Concatenation of two tables together
25. What is the difference between the drill-down group (hierarchical groups) and the cyclic group?
Cyclic groups contain a set of dimensions that can be switched among users, whereas Drill Groups contain a hierarchical list of dimensions used by users to drill down to access detailed levels of the data.
26. What are the types of authorization in QlikView?
Authorization is nothing but permitting the users to access the resources. In QlikView, authorizations are implemented at multiple levels such as-
- Data level
- Sheet Level
- Chart level
- Column level
27. What is an interval match?
Interval match is one of the functions that are useful for tables containing numeric values because it is used to match a numeric value from one table to another table.
28. What are the new features in QV 11?
New features of QV are as follows-
- Container Object-Grid Style
- Conditional enabling of dimensions and expressions
- Granular Chart
- Comparative analysis
29. What is the difference between QVD and QVW?
- QVW: It is a QlikView file saved in binary format with default expression QVW containing tables, charts script, etc.
- QVD: It is a binary CSV file that contains one data table, no layout, and no security.
30. What is the difference between QV Publisher and QV Server?
QV Server is a program installed in a physical server with a number of CALs to authorize users to access QV files on the server. QV Publisher is a program that gives centralized control of all QV files and how to schedule them.
31. What P() and E() in the Set analysis?
In QlikView Set Analysis, a P() function is used to return all possible values while an E() function is used for returning a set of all excluded values.
32. What is the difference between Pick and Match?
The Match() function checks whether the value of a string on an expression is matching with the data value present in a column. The Pick() function is used to return the nth expression along with the string in the list.
33. What is the difference between RDBMS and Associative Data Model?
RDBMS stands for Relational Database Management System, and it stores data in rows and columns of tables, and data is retrieved through SQL queries. An associative database model is comprised of two tables: one for items and one for links.
34. Which tool is provided by QV to get a snapshot view of your table?
Table Viewer is the tool provided by QV that is used to get a snapshot of tables.
35. What type of data connections are used in QlikView?
Type of data connections are used in QlikView
- SAP connectors
36. What macros are used in your application?
We can use macros for the following things-
- To reload the application
- To create objects.
37. What is the use of the extended Interval Match function()?
It is used for slowly changing dimensions.
38. What are the purpose and Uses of QVD files?
- To increase load speed
- Incremental Load
- Ease of Maintenance
- Consolidating data
- Separation of Roles
- Decreasing load on database servers
39. What are the types of QVD Creation?
- By using the Store command
- By using buffer before load/select
- via UI-[chart export]
40. What is the use of the Interval match function()?
It is used to generate data buckets of different sizes.
Top QlikView Server Admin Interview Questions
41. What are the tasks and triggers in QMC (QlikView Management Console)?
Tasks are generated to reload data, whereas triggers are created to schedule and run tasks at a certain time.
42. What is the QlikView server and Publisher?
QlikView Server hosts documents, users, and objects whereas QlikView Publisher is a component of QVS that is responsible for data reduction and distribution, accessing, and managing content. Users need to get a separate license for Publisher.
43. What is the function of different tabs on the QlikView Management console?
There are three tabs present on the QMC – Status, Documents, and Users. There are used for-
- Status- It shows the list of tasks that are already executed and which are currently running on the server. By clicking on this tab, you can check which tasks are successfully completed, which failed, and which are running.
- Documents- This tab contains sub-tabs – source and user document. The source documents contain dashboards created by developers, whereas user documents contain published dashboards.
- Users- It contains data regarding the QlikView server environment and several services and configures users, and clients to access the license system.
44. What are CAL and its types in QlikView?
CAL stands for Clients Access License which is a must to connect to the QlikView Server. There are different types of CAL present in QlikView, and they are as follows-
- Named User CAL: It is user-specific or machine-specific
- Session CAL: Allows different users to control and access different documents
- Usage CAL: It allows users to initiate a session
- Document CAL: It permits to access a specific document.
45. Name some databases that QlikView can connect to.
The following are the databases:
- SQL Server
- DB2, MS Access
46. What kind of Charts do we use in Qlikview Admin?
We generally use a
- combo chart
- scatter chart
- bar chart
- line chart
- grid chart
47. How are the subset ratios and information density different from each other?
Information density is defined as the ratio of null values to the total number of records present in the tables whereas the subset ratio is the ratio of the number of distinct values of a field in a table to the distinct values of the same field in all tables.
48. What is Document-level Auditing in QlikView 11?
Document-level auditing helps administrators to effectively audit user interactions and improve risk management and compliance.
49. In QlikView, what are the objects having only expression and no dimension?
The gauge chart and list box are the objects having only expression and no dimension.
50. What is QlikView?
QlikView is a business intelligence platform that allows users to create, publish, and access interactive data visualizations and reports.
51. What is the QlikView Management Console (QMC)?
The QlikView Management Console (QMC) is a web-based interface that allows administrators to manage and configure the QlikView Server environment.
52. What is the QlikView Distribution Service (QDS)?
The QlikView Distribution Service (QDS) is a service responsible for distributing and scheduling QlikView documents and tasks.
53. What is the QlikView Web Server (QWS)?
The QlikView Web Server (QWS) is a service that provides access to QlikView documents through a web browser.
54. What is the QlikView Directory Service Connector (QDSC)?
The QlikView Directory Service Connector (QDSC) is a service that connects to the QlikView Directory Service (QDS) and allows users to authenticate and authorize access to QlikView documents.
55. What is the QlikView Server Engine (QSE)?
The QlikView Server Engine (QSE) is a service that processes and renders QlikView documents for distribution to users.
56. What is the QlikView Publisher?
The QlikView Publisher is a service that allows users to publish and distribute QlikView documents to the QlikView Server environment.
57. What is the QlikView Management API (QMA)?
The QlikView Management API (QMA) is an API that allows administrators to programmatically manage and configure the QlikView Server environment.
58. What is the QlikView Scripting language?
The QlikView Scripting language is a proprietary programming language used to build QlikView applications. It is used to load and transform data, create associations between data tables, and define visualizations and reports.
60. What is a QlikView load script?
A QlikView load script is a script written in the QlikView Scripting language that is used to load data into a QlikView document.
61. What is a QlikView data model?
A QlikView data model is a logical representation of the data in a QlikView document. It consists of tables and fields, and defines the relationships between them.
62. What is a QlikView object?
A QlikView object is a visual representation of data in a QlikView document. It can be a chart, pivot table, or other type of visualization.
63. What is a QlikView expression?
A QlikView expression is a formula used to calculate values in a QlikView document. Expressions can be used to create calculated fields, or to define the values displayed in visualizations and reports.
64. What is the QlikView Set Analysis syntax?
The QlikView Set Analysis syntax is a set of commands used to define a subset of data to be used in an expression or visualization. It allows users to analyze specific groups of data, rather than the entire dataset.
64. What is a QlikView pivot table?
A QlikView pivot table is a type of visualization that allows users to summarize and analyze data by rearranging the rows and columns in a table.
65. What is a QlikView straight table?
A QlikView straight table is a type of