Informatica Interview Questions- Part( 2 of 2 )

 

Informatica part 2 interview questions
Informatica part 2 interview questions

There are few questions that are most confused while giving answers at the time of interviews. The aim of this post is to share those kind of questions to all the ETL developers. You can read the Complete Informatica Questions and Answers here.

  • What are the objects you can compare?

Sources-You can compare two sources, two source shortcuts, or a source with a source shortcut.
Targets-You can compare two targets, two target shortcuts, or a target with a target shortcut.
Transformations-You can compare two transformations, two transformation shortcuts, or a transformation with a transformation shortcut.
Mappings and mapplets-You can compare two mappings, two mapping shortcuts, or a mapping with a mapping shortcut. You can also compare two mapplets, two mapplet shortcuts, or a mapplet with a mapplet
shortcut.
Instances-Within mappings and mapplets, you can compare two source instances, two target instances, or two transformations. Within mappings, you can also compare two mapplet instances.
Folders– You can compare two folders in the Repository Manager.
Object shortcut versions-You can compare two versions of an object in the Repository Manager.

  • What are NaaN values?

NaN (Not a Number) is a value that is usually returned as the result of an operation on invalid input operands, especially in floating-point calculations. For example, when an operation attempts to divide zero by zero, it returns a NaN result.

Operating systems and programming languages may represent NaN differently. For example the following list shows valid string representations of NaN:

nan
NaN
NaN%
NAN
NaNQ
NaNS
qNaN
sNaN
1.#SNAN
1.#QNAN

The Integration Service converts QNAN values to 1.#QNAN on Win64EMT platforms. 1.#QNAN is a valid representation of NaN.

There are different Informatica forums typically you can join:

  • How String conversion into integer works?

When the Integration Service performs implicit conversion of a string value to an integer value, it truncates the data at the first non-numeric character. For example, you link a string port that contains the value
“9,000,000,000,000,000,000.777” to a Bigint port. The Integration Service converts the string to the bigint value
9,000,000,000,000,000,000.

Top 10 best informatica absolutely new questions for freshers

top-10-best-iformatica-questions
#top-10-best-informatica-questions:

The best method to learn informatica is in the form of Questions and answers. Really you will get good knowlege, if you go through these 400 INFORMATICA INTERVIEW QUESTIONS & ANSWERS as an additional boost.

What is data mart?
A data mart can contain one fact table to address one subject. In such a case,when a number of data marts are integrated to create a data warehouse, it is important that the facts in each table mean the same thing. Such facts (i.e., measures or metrics) that have the same meaning in different data marts are called conformed facts.

What are the different types of datasmarts?
– Stand–alone Data Marts : Data marts that do not interact with other data marts are called stand–alone data marts. On the other hand, data marts can be integrated to create a data warehouse.
– Multi–source Data Mart : A data mart for which the input data is obtained from multiple sources is called a multi–source data mart.
– Personal Data Mart : A data mart for use by individuals such as Chief Executive Officer (CEO), Chief Technology Officer (CTO) or Chief Financial Officer (CFO) is called Personal Data Mart.
– Operational Data Store : ODS is a database system that obtains data from different sources, consolidates it and keeps it at a single location. However, it does not have the sophistication of a data mart or a data warehouse for analytical processing. ODS is generally developed as a pre-cursor for ERP systems.

More: My 3 best selected informatica audio and video books

What is fact table?
A fact table is the central table that contains the measures or facts of a business process.

What is the mapplet?
Mapplet is a set of transformations that you build in the mapplet designer and you can use in multiple mappings.

What is meant by grain?
Granularity of data is a very important factor in the design of fact table. In fact table, we can represent data at different atomic levels, called grains.

What is difference between view and materialized view?
Views contains query whenever execute views it has read from base table. A view which is physically stored in a database. Learning on two types of views-read only and updatable is good bet for interviews.

Materialized views allow query performance to be enhanced by precalculating costly operations.

What is surrogate key?
A system generated artificial primary key that is not derived from any data in the database. It is similar to the object identifier in an object oriented system.

What is a folder?
Folder contains repository objects such as sources, targets, mappings, transformation which are helps logically organize our data warehouse.

What is pivot?
The pivot (or rotate) operation rotates the axes of a cube to provide an alternative presentation of the data.

What is the difference between mapping and session?
Maping : It is a set of source and target definitions linked by transformation objects that define the rules for transformation.

Session : It is a set of instructions that describe how and when to move data from source to targets.

My 3 best informatica Books for an awesome reference

Informatica books
[ Informatica books ]
INFORMATICA INTERVIEW QUESTIONS & ANSWERS: Hands on tips & questions to crack the interview – This book covers all 400 interview questions. These covers almost all sections of Informatica. These are highly useful for beginners to professionals. You can get these copies quickly.

One book that contain all the questions at one place. This FREE version of informatica you need to have handy for more practice purpose.

Tips to practice:

  • Buy a new laptop at 20 to 25K
  • Install informatica FREE version as per instructions
  • Use tutorial or complete reference and start practice all the transformations.
  • Initially you may get bored, but make a strong will to do practice 2 hours daily. This is one of the best tool with which you can get fat pay package.

Informatica power center 9.x – This is complete reference with illustrative examples on informatica. It covers all the transformations and with project examples. Much useful information for learners and professionals who want to update their knowledge.

The pay scale for ETL developers is more attractive in India and USA.

Informatica Power center for ETL developers and Video Tutorial – I am sure that you will be more than happy to access given course and this book. If you want to become expert in world’s most commonly used ETL tool, you have come to right place. With this tutorial you will know everything you need to know and able to work as Informatica Developer. Start earning minimum $80,000 per year by learning Informatica. All topics are covered with real time project examples which will give you full confidence to stand as ETL developer.