What are th pros of Qlikview?

Pros of Qlikview:

• BI Agility--BARC's BI Survey 10 gave highest score to QlikView for its ‘Agile BI’ ability. Agile Business Intelligence delivers faster and better results to help business grow more effective.
• Implementation--QlikView is committed to bring the fastest and smooth implementation in a very short span of time.
• User-driven Approach--QlikView utilizes user-driven approach to Business Intelligence. The intuitive interface is easy to use and builds charts with negligible coding.
• Simplicity and Ease of Use--The software is extremely simple and easy to use. It is extremely fast and requires very little time and effort of staff members. This adds to the general productivity of the entire management and administration. The dashboards and reports can be easily navigated and understood even by non-IT users.
• Flexibility--Every organization has its own unique data and different set of requirements. QlikView offers incredible flexibility to its users. They can set and tweak the various objects to the minutest levels keeping even the smallest aspect in consideration. It also incorporates ETL (Extract, Transform, Load) Engine. Though there is a cost to it, yet this is extremely helpful in cleansing ordinary data.
• Architectural Strength--QlikView utilizes the recent developments of IT, viz. multi-core processors, faster and cheaper memory and higher bandwidth. This advancement has given them the architectural strength which helps in reducing the cost, infrastructure resources and overall team size involved in offering BI Solutions.
• Dashboard--Based on avant-garde prebuilt dashboard applications, QlikView offers an intuitive and innovative set of dashboard which is customizable. Its associative dashboards along with advanced search capabilities make it a perfect fit for business intelligence and data visualization requirements.
• Data Consolidation--The QlikView tools consolidate data in a highly effective manner. Manual reporting and analysis has scope for error.  This eliminates the scope of human error. It also shows up as good saving in terms of money and time.
• Filtering of Data--The filtering tools of the application are so powerful that they render the graphs and tables very fast. It is easy to set up filtering of all sorts to get data in useful visual form.
• Use of RAM of the server--QlikView handles data input very smoothly. It keeps the data in memory stored in the RAM of the server. This data is simultaneously available for multiple users. This makes the queries faster and the user experience with data exploration and amelioration is faster.
• Identification of  operational inefficiencies--After utilizing the front-end information available for the organization, it can process the information and help in identifying the areas of operational inefficiencies. When the organization gets present to these facts, it is able to take significant steps for improving the efficiency of the system.

Can you explain start schema in Qlikview?

Star Schema:

A start schema model is a type of data model in which multiple dimensions are linked to a single fact table. Of course, in bigger models there can be multiple facts tables linked to multiple dimensions and other fact tables. The usefulness of this model lies in performing fast queries with minimal joins among various tables. The fact table contains data, which are measures and have numeric values. Calculations are applied on the fields in the fact table. The unique keys of the dimension tables are used in linking it to the fat table, which also has a key usually with the same field name. Therefore, the Fact table contains the keys from the entire dimension table and forms a concatenated primary key used in various queries.

What are the important features of Qlikview?

• Data visualizations
• Dynamic BI ecosystem
• Interact with dynamic apps, dashboards and analytics
• Search across all data
• Natural search
• Default and custom connectors
• App scripts and Workbench
• Roles & Permissions
• Secure, real-time collaboration
• Advanced reporting templates
• Custom reports
• Mobile-ready

What is Generic Load in QlikView?

Qlikview Generic Load is the load which is used in Qlikview for Generic database. Generic database is used in Qlikview to define the table in the transformation step. A Generic key word is used for defining the Generic Data base in the Qlikview. For Generic table we have to need at least three fields in the table and the second last column in the arbitrary key attribute in the table and the last one is the Value for the table.

Optimized and UN optimized QVD Load Situations?

Optimized load is much faster and therefore preferable, especially for larger data sets. Optimized loads are possible if no transformations (calculations) are made during the load, and no (almost) filtering is done in a WHERE clause.

The only acceptable filter is using function Exists: 
WHERE Exists (Field) 
So for example this load can't be optimized: 
Load * From ... WHERE Country = 'US' 
But this load can: 
Load * From ... WHERE EXISTS (Country) 

On the other hand, the only time you want the load not to be optimized, is if you load a Mapping table from a QVD file. In this case, Optimized load doesn't quite work, so you want to make the load non-optimized deliberately.

What is Mapping Load & Apply Map ()?

Mapping Load: The mapping prefix is used on a load or select statement to create a mapping table, these tables are different from other tables. They will be stored in separate area of memory and used as mapping tables during script execution. After execution they will automatically drop.

Ex. Mapping (Load Statement/Select Statement) 

Apply Map: used for mapping data from one source to another at load time. 

Ex. Apply map(Map name, expr,[default expr])

What is the difference between ODBC, OLE DB & JDBC?

The differences between these two data access protocols are technical, but in the most general terms, OLE DB is newer, more advanced, and compatible with a wider selection of database technologies. In addition, OLE DB is more general, in that it includes the ODBC functionality. 
Technically speaking, ODBC (Open Database Connectivity) is designed to provide access primarily to SQL data in a multi-platform environment. OLE DB (Object Linking and Embedding Database) is designed to provide access to all types of data in an OLE Component Object Model (COM) environment. OLE DB includes the SQL functionality defined in ODBC but also defines interfaces suitable for gaining access to data other than SQL data.
A query generated via ODBC is functionally similar to a query generated by OLE DB. However, be aware that if you generate a query (via STATISTICA Query) using an ODBC connection, STATISTICA uses OLE DB to connect to the ODBC connection. Because there is an intermediate connection, ODBC queries may be slower than OLE DB queries.

Interview Questions on QlikView Scripting

What is the use of Cross table prefix in QlikView Load Script?
What is the difference between Map Using and Mapping Load?
Synthetic Keys in QlikView and how & when to avoid them?
Different flavors’ of Joins in QlikView?
What is the difference between Join & Keep?
How do you use having clause (SQL Equivalent) along with Group by in QlikView?
Explain Interval Match function in QlikView?
Explain Concatenation, No Concatenation & Auto Concatenation?
Explain how to implement Incremental Load?
What is Circular Loop and how do you avoid it?
Explain Exists () function in QlikView and when do you use this function?
What is Generic Load in QlikView?

QlikView Interview Questions on QlikView Security

Describe Section Access architecture?
What is the difference between Authentication & Authorization in QlikView? And how to implement them?
What is the difference between File System Security vs Section Access?
Explain “Strict Exclusion” while implementing Section Access and what are the implications of not using this option?
How do you implement Section Access on hierarchy based data?

QlikView Server & Publisher Interview Questions

What are the multiple protocols defined for client communication with QVS?
Explain different communication encryptions for Windows Client & AJAX Client?
What is the use of Anonymous User Account in QVS?
What are the different types of CALs and explain them?
What are the different editions of QlikView Server?

QlikView Expression Language/UI Interview Questions

Explain Aggr Function? 

What is the use of First Sort Value in QlikView? 

What are Set Modifiers and Set Identifiers? 

What is P() & E() and where do you use them? 

What is the difference between Value List() and Value Loop()? 

What is Partial Reload? and why do you use “ONLY” Qualifier? 

What is the difference between Cyclic Group & Drill down Group? 

Explain alternate states and where do you use them?