Good Qlikview Interview Questions and answers
Qustion.1 Explain Qlikview architecture?
Answer: QlikView
deployments have three main infrastructure components:
1.QlikView Developer : Is a
Windows-based desktop tool that is used by designers and developers to create
1) a data extract and transformation
model and
2) to create the graphical user
interface (or presentation layer).
2.QlikView Server (QVS) : Handles the
communication between clients and the QlikView applications. It loads QlikView
applications into memory and calculates and presents user selections in real
time.
3.QlikView Publisher: Loads data from
different data sources (oledb/odbc, xml, xls), reduces the QlikView application
and distributes to a QVS.
Because QlikView Server and Publisher
have different roles and handle CPU and memory differently it’s considered a
best practice to separate these two components on different servers.
Question.2 Set analysis in qlikview ?
Answer: Used for set
of groups ..mostly used in arrgeted function like sum (year) used
sales of current year VS last year.
Question.3 What is Synthetic key and
how to avoid it in QlikView?
Answer: It is
undesirable to have multiple common keys across multiple tables in a QlikView
data structure. This may cause QlikView to use complex keys (a.k.a. synthetic
keys) to generate the connections in the data structure. Synthetic keys are
generally resource heavy and may slow down calculations and, in extreme cases,
overload anapplication. They also make a document harder to understand and
maintain. Thereare some cases where synthetic keys cannot be avoided (e.g.
Interval Match tables),but, in general, synthetic keys should always be
eliminated, if possible.
1. comment the fileds in load script
2. rename the fileds in load script
3. rename the fileds using UNQUALIFY
operator;
Question.4 Difference between keep and
joins ?
Answer Left Keep and Left
join gives the same output. The only difference is that Left Keep keeps the
Table separate in Data Model, whereas Left join merges the Tables that are
joined.
Question.5 Difference between Straight
table and pivot table ?
Answer: Pivot Table –
1) A pivot table is better at
grouping: you can easily see which group a specific row belongs to, and a group
can have a subtotal.
2) You can also display a pivot table
like a cross table (one or several horizontal dimensions).
3) But when you sort a pivot table,
you have to sort it first according to the first dimension, then according to
the next, etc.
You cannot sort it
any way you want.
Straight Table-
A straight table is better at sorting
than a pivot table: you can sort it according to any column.
But it is not so good at grouping.
Subtotals are not possible, for instance.
Question.6 Which graph will you used for
two years difference sale ?
Answer: BAR Graph
Question.7 What is Incremental Load in
qlikview?
Answer: As BI apps are
expected to deal with larger and larger amounts of data the amount of time that
it takes to retrieve that data becomes a serious issue. This could be due
to shear volume of data or the need for frequent refreshes. Either way, you do not
want to be pulling all of the data all of the time. What you want to be able to
do is just pull the data that has changed, append to that the data that you
stored away previously and then get back to the business of analyzing.
This will reduce load on the source database, the network infrastructure and
your QlikView server.
Question.8 Whta is Inline memory in
QlikView ?
Answer: Create table or add
field to table .
Question.9 what is Set and let in QlikView
and difference between it?
Answer: SET or a LET
statement is often usedTo define the variable. The SET statement is used when
you want a variableto hold the string or numeric value that is to the right of
the Equal (=) sign.
The LET statement is used when you
need to evaluate what is to the right of the Equal sign
e.g
setmyVar=5*2 the result
is “5*2″
Let myVar=5*2 the result
is “10″
Question.10 Explain QlikView Resident Load?
Answer: Create a new
logical table in QlikView, based on a previously loaded (resident) table.
Question.11 What is Apply Map (Mapping
Tables)?
Answer: Sometimes you need
to add an extra field to a table to use a combination of fields
from different tables, or you want to
add a field to clean up the data structure. Qlik- View has an effective way to
add single fields to a table called mapping tables. syntax — mapping (
load statement | select statement )
applymap( ‘mapname’, expr, [ ,
defaultexpr ] )
Question.12 What is Dimensions ( What is
difference between Expression and Dimension)?
Answer: Each data
warehouse consists of dimensions and measures. Dimensions allow data analysis
from various perspectives. For example, time dimension could show you the
breakdown of sales by year, quarter, month, day and hour. Product dimension
could help you see which products bring in the most revenue. Supplier dimension
could help you choose those business partners who always deliver their goods on
time. Customer dimension could help you pick the strategic set of consumers to
whom you’d like to extend your very special offers.
Question.13 Explain about Normalized Data?
Answer: Well
Structured Form of Data, which doesnt have any repetition or redundancy of
data. Its a kind of Relational data. Its mainly used in OLTP kind of stuffs
Denormalized Data – Its a whole bunch of data without any relationship among
themselves, with redundancy of data. Its mainly used in OLAP kind of stuffs.
Question.14 What Is Star Sechma ?
Answer: A star schema is
the simplest form of dimensional model, in which data is organized into facts
and dimensions. A fact is an event that is counted or measured, such as a
sale or login. A dimension contains reference information about the fact,
such as date, product, or customer. A star schema is diagramed by surrounding
each fact table with its associated dimensions table. The output diagram
resembles a star.
Star Schema Definition : A means of
aggregating data based on a set of known dimensions. It stores data
multidimensionality in a two dimensional Relational Database Management System
(RDBMS), such as Oracle.
Question.15 What is Snowflaking Schema ?
Answer: Snowflake Schema:
An extension of the star schema by means of applying additional dimensions to
the Dimensions of a star schema in a relational environment. Snowflaking is a
form of dimensional modeling; dimensions are stored in multiple relational
dimension tables. A snowflake schema is a variation of the star schema.
Snowflaking is used to improve the performance of specific queries. The
schema is diagramed with each fact surrounded by its associated dimensions as
in a star schema, and those dimensions are further related to other dimensions,
branching out into a snowflake pattern.
Question.16 What is Central Link Table?
Answer: In the event of
multiple fact tables QlikView In-Memory Technology allows us to create a
central link table that only contains the existing data combinations. Instead
of Joining the tables the event dimensions can be merged (CONCATENATED) in to
one central Link table. This link table can then be linked back to the event measures
one side and the dimension tables on the other.
Question.17 What is binary load ?
Answer: Binary load is
loading data from another QV file. For example, you have application
A.qvw. You can create another application B.qvw with script binary A.qvw.
binary file where:
file ::= [ path ] filename
Examples:
Binary customer.qvw;
Binary c:\qv\customer.qvw;
The path is the path to the file,
either absolute, or relative to the .qvw file containing this script line.
Question.18 What is Container ?
Answer: A container object
can be used to hold multiple charts. You can use a container object to
put multiple charts in the same box. All charts will appear in the same window
but only one chart will appear active at a given time. You can click the chart
title to switch or toggle between charts. A word of advice: Use containers with
caution. They form linked objects and might affect the properties of all linked
objects.
Question.19 What is a synthetic key?
Answer: It is a field
that contains all possible combinations of common fields among tables.
1.What kind of chart we use in Qlikview?
We
generally uses bar chart, line chart, combo chart, scatter chart, grid chart,
etc.
2.Explain Set analysis in qlikview ??
It is
used for set of groups. Mostly used in arrgeted function like sum (year)etc.
3.Define Trellis chart?
In
Trellis chart we can create array of chart based on first dimension. Bitmap
chart are also made of trellis display.
4Explain Mini Chart?.What do you mean by sub
reports and how we can create them?
With
the help of Mini Chart we can set type of modes instead of values in table
mode. We can also change the colors.
5.What is Pivot Table?
Pivot
Table:
A pivot table is better at the time of grouping. We can also show pivot table like a cross table which is a beneficial feature. But there is one disadvantage of it which is if we have to sort a pivot table than we have to sort it first according to the first dimension then to the next.
A pivot table is better at the time of grouping. We can also show pivot table like a cross table which is a beneficial feature. But there is one disadvantage of it which is if we have to sort a pivot table than we have to sort it first according to the first dimension then to the next.
6.Which graph we will use for two years
difference sale ?
BAR
Graph we will use.
7.What is Straight Table?
A
straight table is much better at the time of sorting as compared to the pivot
table as we can sort it according to any column as per our choice. But it is
not good for grouping purpose.
8.How many dimensions we can use in Bar chart?
We can
use only two dimension
9.WhichQlikview object has only expression and
no dimension?
Gauge
chart and list box have only expression and no dimension.
10.How we can use Macros in our application?
We can
use macros for various purposes like for reloading the application and to
create a object.
11.What do you understand by layers in
Qlikview?
The
layer are basically set on the sheet object properties layout where bottom,
top, normal respective to the number -1,0 and 1.
12.What is Dimensions?
Dimensions
allow data examination from various perspectives.
13.Explain about Normalized Data?
Well
Structured Form of Data, which doesnt have any repetition or redundancy of
data. Its a kind of Relational data. Its mainly used in OLTP kind of stuffs
Denormalized Data – Its a whole bunch of data without any relationship among
themselves, with redundancy of data. Its mainly used in OLAP kind of stuffs.
14.What Is Star Sechma ?
The
simplest form of dimensional model, in which data is prearranged into facts and
dimensions is known as Star schema.
15.What is Snowflaking Schema ?
A
snowflake schema is a difference of the star schema. Snowflaking is used to
improve the presentation of particular queries.
16.Explain interval match?
The
internal match is prefixes with the load statement which is used for connecting
different numeric values to one or more numeric interval.
17.Explain internal match function()?
Internal
match fuction is used to generate data bucket of different sizes.
18.What is Container ?
A
container object is used to keep multiple charts. We can use a container object
to keep many charts in the same box.
19.What do you understand by extended interval
match function()?
Extended
interval match function() is used for slowly changing the dimensions.
20.what are the new features in QV 11?
Container
Object;Granular Chart Dimension Control; Actions like, clear filed; meta
data,etc are the new features in QV 11.
21.Explain joins and its types?
Join is
used to convert the given data and whenever we are using joins for converting
data its is known ad Data Merging.
It has many types:
a. Left join
b. Right join
c. Inner join, etc
It has many types:
a. Left join
b. Right join
c. Inner join, etc
22.What is Left Join?
Left
join specifies that the join between the two tables should be left join, it
uses before the word join. The resulting table only contain the combination
among two tables with the full data set from the first table.
23.Define right join?
Right
join specifies that the join between the two tables should be right join, it
uses before the word join. The resulting table only contain the combination
among two tables with the full data set from the second table.
24.Explain Inner Join?
Inner
join specifies that the join between the two tables should be inner join. The
resulting table should contain the full data set from both the sides.
25.What are modifiers?
Modifiesr
deals with the Fields name.
For example: sum({$}Sales)
Returns the sales for current selection, but with the selection in “Region” is removed.
For example: sum({$}Sales)
Returns the sales for current selection, but with the selection in “Region” is removed.
26.Explain Identifiers Syntax?
1. 0-
Represents the empty set
2. 1- Represents the full sets of records
3. $-Represents the record of current selection
4.$1-Represents the previous selection
5.$_1-Represents the next selection
6. Bookmark01-Represents the Bookmark name
2. 1- Represents the full sets of records
3. $-Represents the record of current selection
4.$1-Represents the previous selection
5.$_1-Represents the next selection
6. Bookmark01-Represents the Bookmark name
27.Explain 3-tier architecture of Qlikview
Application?
1-tier:
Raw data is loaded and we create QVD
2-tier: QVD is converted in business login and the requirement of business and data model is created.
3-tier: Reading all QVD from 2-tier and we make a single QVW.
2-tier: QVD is converted in business login and the requirement of business and data model is created.
3-tier: Reading all QVD from 2-tier and we make a single QVW.
28.How does Qlikview stores the data
internally?
Qlikview
stores the data in QVD as QVD has data compression capability. Qlikview has
better performance than other BI because of its memory analytics approach.
29.Explain the restrictions of Binary load?
Binary
Load can be used for only one application means we can only read the data from
one QVW application and moreover set scripts is also a restriction.
30.Differentiatebetwwen subset Ratio and
Information Density.
Subset
Ratio: It is used for easily spot problem in key field association.it is only
relevant for key fields since they are present in multiple tables and do not
share the same value.
Information Density: It is the field which contain the percentage of row which contain the non-null value.
Information Density: It is the field which contain the percentage of row which contain the non-null value.
31.what is the use of Optimized Load?
Optimized
load is much faster and preferable especially for large set of data. It is
possible if n otransformation are made at the time of load and no filtering is
done.
32.Differentiate between keep and joins?
Keep
and joins do the same functions but in keep creates the two tables whereas join
only creates the one table. Keep is used before the load or select statements.
More Qlikview Interview Questions
More Qlikview Interview Questions
33.Define synthetic Key?
Synthetic
key is the key where two or more tables consists more than one common column
between them is called as synthetic key.
34.What is incremental load in Qlikview?
Incremental
load is nothing but loading new or changed records from the database. With the
help of QVD files we can use incremental Load.
35. Differentiate between set and let option
in Qlikview??
Set: it
assigns the variable without assesses the expression.
Let: it assigns the variable with assesses the expression.
Let: it assigns the variable with assesses the expression.
36.DefineQlikview Resident Load.
Resident
load is a part of loading data in Qlikview application. It is used for loading
data in tables which is already loaded in Qlikview application.
37.How we can optimize QV application?
It can
be optimized by creating the data into qvds. When complete qvw application is
changed into qvd than this qvd will be store in the RAM.
38.What is mapping load?
Mapping
load is used to create the mapping table that can be used for replacing field
value and field names.
39.Define apply map.
apply
map is used to add fields to the tables with the help of other tables. It can
be used as joins.
40.What is concatenation?
It
means sequence of interconnected things i.e. any column or row which is related
to each other can be connected through concatenation.
41.DefineNoConcatenation.
NoConcatenation
prefix is used to forced the identical tables as two separate internal tables.
42.Define connect statement.
It is
used to establish a connection the connection to database with the help of ODBC
or OLEDB interface.
43.What do you understand by Fact
constellation Schema?
It is a
logical database structure of data Warehouse . It is design with the help of De
Normalized Fact..
44.What do you mean by RDBMS?
It
stands for relational Database management System. It arrange the data into
respective column and rows.
45What do you understand by the term CAL in
Qlikview?
Every
client need a CAL to get connected with Qlikview Server. The CALS are taken up
with Qlikview Server and tied with the server serial number.
46.Differentiate between QV server and
publisher?
QV
Server is a program that is installed on computer with various CALS which allow
user to access QV Files on the server. Publisher is a program which manages
centralized control on our QV files and manages them how and when the are
loaded and distributed.
47.What do you understand by snapshot view of
the table?
By this
option we can see number o tables and related associations.
48.How we can bring data into qv?
We use
ODBC, OLEDB, SAP connectors kind of data connections.
49.How we can handle Early Arriving Facts.
We can
load data from ODBC, OLEDB, SAP connectors , by select statements and we can
also load files like excel, word, etc. by using Table Syntax.
50.What type of data we generally use?
We use
flat files, excels, QVDs, etc ad data.
51. Explain about QlikView?
QlikView
is the Business Intelligence tool used by the University of St Andrews. Data
from different University systems is combined and presented in a single
dashboard in an easy and understandable way.
QlikView
dashboards at the University of St Andrews are built on the following
principles:
•
Dashboards must be effective to use
• Dashboards must support users in carrying out their tasks
• Dashboards must provide the right kind of functionality
• It must be easy to learn how to use a dashboard
• It must be easy to remember how to use a dashboard
• To use QlikView, you do not need to have technical expertise in information systems, just a willingness to learn how it can support you.
• Dashboards must support users in carrying out their tasks
• Dashboards must provide the right kind of functionality
• It must be easy to learn how to use a dashboard
• It must be easy to remember how to use a dashboard
• To use QlikView, you do not need to have technical expertise in information systems, just a willingness to learn how it can support you.
52. What are the benefits of using QlikView?
As the
name suggests, QlikView is a combination of quick and click and these features
make it intuitive and easy to use. Users can visualize data, search multiple
data sets, create ad hoc reports, and view patterns and trends in data that may
not have been visible in other reports.
QlikView is
• Flexible – dashboards are web based and accessible from desktop computers and mobile devices
• Interactive – users are able to drill down and select particular data within charts or tables
• Usable – users can see large amounts of data effectively and efficiently
• Scalable – useful for multiple business processes at analytical, operational and strategic levels
QlikView is
• Flexible – dashboards are web based and accessible from desktop computers and mobile devices
• Interactive – users are able to drill down and select particular data within charts or tables
• Usable – users can see large amounts of data effectively and efficiently
• Scalable – useful for multiple business processes at analytical, operational and strategic levels
53. How is QlikView 11 different from QlikView
10?
QlikView
11 brings new levels of capability and manageability to the QlikView Business
Discovery platform. In this release, we focused our investments on five value
propositions:
•
Improve collaborative decision making with Social Business Discovery
• Gain new insights into opportunities and threats and relative business performance with comparative analysis
• Expand QlikView usage to additional devices, including smartphones, with mobile Business Discovery
• Enable a broad spectrum of users to jointly develop QlikView apps with QlikView’s rapid analytic app platform capabilities
• Improve the manageability and performance of QlikView with new enterprise platform capabilities.
• Gain new insights into opportunities and threats and relative business performance with comparative analysis
• Expand QlikView usage to additional devices, including smartphones, with mobile Business Discovery
• Enable a broad spectrum of users to jointly develop QlikView apps with QlikView’s rapid analytic app platform capabilities
• Improve the manageability and performance of QlikView with new enterprise platform capabilities.
54. What is QlikView comparative analysis?
Business
users can quickly gain new kinds of insight when analyzing information in
QlikView, with new comparative analysis options. App developers can now create
multiple selection states in a QlikView app; they can create graphs, tables, or
sheets based on different selection sets.
55. What mobile device platforms does QlikView
11 support?
QlikView
11 delivers mobile functionality for Apple iOS and Android tablets and
smartphones. QlikView supports Android tablets when the following conditions
are met:
•
QlikView Server version 10 SR3 or later
• The native browser, not a downloaded one
• Currently our HTML5 web apps support only Apple and Android handhelds. Because many Black Berry are older devices that don’t fully support HTML5 (and many are non-touch), we don’t have a web-based solution for them at this time.
• The native browser, not a downloaded one
• Currently our HTML5 web apps support only Apple and Android handhelds. Because many Black Berry are older devices that don’t fully support HTML5 (and many are non-touch), we don’t have a web-based solution for them at this time.
56. What is document-level auditing in
QlikView 11?
New
optional settings within QlikView Management Console enable administrators to
more effectively audit user interactions. Administrators can audit QlikView
usage not only at the system level (the entire QlikView Server), but down to
the document level.
57. What are the key differences between
QlikView and any other standard statistical software package (SAS, SPSS)?
Key
difference is in terms of the database used. QlikView offers a quite simple
visualization that matches the MS excel filtering. SAS is useful in case of Meta
data while SPSS is good for analysis.
In comparison of the above three, QlikView is most user friendly and fast in terms of generating diverse dashboards/templates.
In terms of calculations, advanced statistics options are limited in QlikView.
For market research and analysis SPSS has direct facility algorithms.
In comparison of the above three, QlikView is most user friendly and fast in terms of generating diverse dashboards/templates.
In terms of calculations, advanced statistics options are limited in QlikView.
For market research and analysis SPSS has direct facility algorithms.
58. What are QlikView annotations?
With
the new annotations collaboration object QlikView users can engage in threaded
discussions about QlikView content. A user can create notes associated with any
QlikView object. Other users can then add their own commentary to create a
threaded discussion. Users can capture snapshots of their selections and
include them in the discussion so others can get back to the same place in the
analysis when reviewing notes and comments. QlikView captures the state of the
object (current selections), as well as who made each note and comment and
when, for a lasting record of how a decision was made.
59. What are the main features of QlikView?
QlikView
offers the following features:
•
Dynamic BI Ecosystem
• Data visualization
• Interacting with dynamic apps, dashboards and analytics
• Searching across all data
• Secure, real-time collaboration
• Data visualization
• Interacting with dynamic apps, dashboards and analytics
• Searching across all data
• Secure, real-time collaboration
60. What are the differences among QlikView
Server editions?
The
differences are:
QlikView
Server Enterprise Edition (EE) is available for
customers looking to support a large number of users and integrate into
enterprise environments. It includes features such as:
• Unlimited documents
• Integration with third party security systems
• Server clustering
• Small Business Edition (SBE) is designed to be used in smaller deployments.
It has the following limitations:
• For use only with Named and Document CALs
• Limited to 25 Named User CALs
• Limited to 100 Document CALs
• No support for additional servers
• Only supports Windows Active Directory to handle security and access control
• Unlimited documents
• Integration with third party security systems
• Server clustering
• Small Business Edition (SBE) is designed to be used in smaller deployments.
It has the following limitations:
• For use only with Named and Document CALs
• Limited to 25 Named User CALs
• Limited to 100 Document CALs
• No support for additional servers
• Only supports Windows Active Directory to handle security and access control
Information
Access Server (IAS) is an edition of QlikView Server designed to power public
Internet sites. This edition:
• Includes the add-on QlikView Real Time Server
• Is licensed for uncapped number of user but limited to one QlikView document
• Must be set to anonymous mode only and authentication must be off
• Requires that the QlikView server be on the public Internet and publicly accessible
• Requires that the URL for accessing the site powered by the QlikView Server be publicly accessible
• Requires that no QlikView client (e.g., QlikView Desktop, Internet Explorer plug-in, Ajax) can access the QlikView Server (all user interfaces must be built by the customer manually or with QlikView Workbench)
• Includes the add-on QlikView Real Time Server
• Is licensed for uncapped number of user but limited to one QlikView document
• Must be set to anonymous mode only and authentication must be off
• Requires that the QlikView server be on the public Internet and publicly accessible
• Requires that the URL for accessing the site powered by the QlikView Server be publicly accessible
• Requires that no QlikView client (e.g., QlikView Desktop, Internet Explorer plug-in, Ajax) can access the QlikView Server (all user interfaces must be built by the customer manually or with QlikView Workbench)
QlikView
Extranet Server (QES) is an edition of QlikView Server designed to extend
QlikView functionality to external users via an extranet. QES:
• Requires authentication. Users must be external to the purchasing organization (customers, partners, etc.).
• Restricts server access to the Ajax client and mobile clients
• Provides the option to customize the QlikView application via the included QlikView Workbench
• Supports a maximum of 3 QlikView documents
• Supports session CALs and usage CALs only
• Requires authentication. Users must be external to the purchasing organization (customers, partners, etc.).
• Restricts server access to the Ajax client and mobile clients
• Provides the option to customize the QlikView application via the included QlikView Workbench
• Supports a maximum of 3 QlikView documents
• Supports session CALs and usage CALs only
