Interview Questions.

Q1. What Are The Differences Between Informatica Power Center Versions 6.2 And 7.1, Also Between Versions 6.2 And 5.1?

The fundamental difference between informatica five.1 and 6.1 is that in 6.1 they introduce a new factor called repository server and in region of server manager(five.1), they introduce workflow manager and workflow reveal.

Q2. Is A Fact Table Normalized Or De-normalized?

A truth table is always DENORMALISED table. It includes statistics from measurement desk (Primary Key's) and Fact table has overseas keys and measures.

Q3. What Is A Source Qualifier?

When you add a relational or a flat record supply definition to a mapping, you want to connect it to a Source Qualifier trformation. The Source Qualifier represents the rows that the Informatica Server reads when it executes a consultation.

Q4. How Many Types Of Dimensions Are Available In Informatica?

The sorts of dimensions to be had are:

Junk measurement

Degenerative Dimension

Conformed Dimension

Q5. At The Max How Many Trformations Can Be Us In A Mapping?

In a mapping we can use any wide variety of trformations relying at the venture, and the included trformations inside the unique associated trformations.

Q6. What Is The Difference Between Filter And Lookup Trformation?

Filter trformation is an Active trformation and Lookup is a Passive trformation.

Filter trformation is used to Filter rows based on condition and Lookup is used to look up data in a flat record or a relational table, view, or synonym.

Q7. How Can We Use pmcmd Command In A Workflow Or To Run A Session

By the use of command in the command venture there is a alternative pression. We are able to write appropriate command of pmcmd to run workflow.

Q8. What Is Difference Between Informatica 7.1 And Abinitio?

There is a lot of distinction between informatica and AbInitio:

In AbInitio we are the usage of 3 parallelism however Informatica using 1 parallelism.

In Ab Initio no scheduling alternative we can time table manually or pl/sq. Script however informatica includes 4 scheduling alternatives.

In Ab Inition includes co-working gadget however informatica isn't always.

Ramp time may be very speedy in Ab Initio examine than Informatica.

Ab Initio is person friendly than Informatica.

Q9. When We Create A Target As Flat File And Source As Oracle. How Can I Specify First Rows As Column Names In Flat Files?

Use a pre sq. Declaration., however this is a hard coding technique. If you convert the column names or installed more columns in the flat file, you'll should trade the insert statement.

You can also attain this through converting the setting in the Informatica Repository manager to display the columns heading. The best drawback of this is that it will be implemented on all the files so that it will be generated by means of this server.

Q10. How To Load Time Dimension?

We can use SCD Type half of/three to load any Dimensions based totally at the requirement. We can also use manner to populate Time Dimension

Q11. What Is Difference Between Maplet And Reusable Trformation?

Maplet :

one or greater trformations.

Set of trformations that are reusable.

Reusable trformation :

simplest one trformation

Single trformation which is reusable.

Q12. How To Import Oracle Sequence Into Informatica?

Create one method and declare the series in the process, ultimately call the system in informatica with the assist of saved process trformation.

Q13. How To Read Rejected Data Or Bad Data From Bad File And Reload It To Target?

Correction the rejected information and send to goal relational tables using load order software. Find out the rejected information through the use of column indicator and row indicator.

Q14. Compare Data Warehousing Top-down Approach With Bottom-up Approach.

Top down

ODS-->ETL-->Datawarehouse-->Datamart-->OLAP

Bottom up

ODS-->ETL-->Datamart-->Datawarehouse-->OLAP

Q15. What Is The Default Source Option For Update Strategy Trformation?

Default alternative for replace strategy trformation is dd_insert or we will put '0' in session stage records pushed.

Q16. Why We Use Stored Procedure Trformation?

A Stored Procedure trformation is an vital tool for populating and preserving databases. Database administrators create saved techniques to automate time-ingesting duties which are too complicated for preferred SQL statements.

Q17. What Are Main Advantages And Purpose Of Using Normalizer Trformation In Informatica?

Narmalizer Trformation is used particularly with COBOL assets where maximum of the time statistics is saved in de-normalized format. Also, Normalizer trformation may be used to create multiple rows from a unmarried row of records.

Normalizer Trformation read the records from COBOL Sources.

It guide Horizontal Pivot .It is a processing of unmarried enter right into a multiple output

Q18. Which All Databases Powercenter Server On Windows Can Connect To?

PowerCenter Server on Windows can hook up with following databases:

IBM DB2

Informix

Microsoft Access

Microsoft Excel

Microsoft SQL Server

Oracle

Sybase

Teradata

Q19. Which All Databases Powercenter Server On Unix Can Connect To?

PowerCenter Server on UNIX can connect to following databases:

IBM DB2

Informix

Oracle

Sybase

Teradata

Q20. Define Informatica Repository?

The informatica repository is at the middle of the informatica suite. You create a set of metadata tables in the repository database that the informatica utility and equipment get entry to. The informatica patron and server get entry to the repository to store and retrieve metadata.

Q21. Which Is Better Among Connected Lookup And Unconnected Lookup Trformations In Informatica Or Any Other Etl Tool?

If you're having defined supply you could use connected, supply isn't always well defined or from distinctive database you may cross for unconnected.

Connected and unconnected research depends on scenarios and performance If you are seeking out a unmarried fee for appearance up and the cost is like 1 in a thousand then you ought to go for unconnected research. Performance sensible its higher as we are not regularly the usage of the trformation. If multiple columns are returned as research cost then one have to cross for linked lookup.

Q22. What Is The Difference Between Informatics 7x And 8x And What Is Latest Version?

Java Trformation to be had within the 8x version and it is not available in 7x model.

Q23. Differences Between Normalizer And Normalizer Trformation.

Normalizer : It is a trformation in particular using for cobol assets. It alternate the rows into columns and columns into rows.

Normalization : To get rid of the redundancy and inconsistency.

Normalizer Trformation : can be used to reap more than one columns from a unmarried row.

Q24. What Type Of Repositories Can Be Created Using Informatica Repository Manager?

Informatica PowerCenter includeds following kind of repositories :

Standalone Repository : A repository that capabilities for my part and this is unrelated to every other repositories.

Global Repository : This is a centralized repository in a website. This repository can comprise shared items across the repositories in a domain. The items are shared via international shortcuts.

Local Repository : Local repository is within a site and it’s not a worldwide repository. Local repository can connect to a worldwide repository the usage of global shortcuts and might use objects in it’s shared folders.

Versioned Repository : This can either be neighborhood or global repository but it allows version manipulate for the repository. A versioned repository can shop more than one copies, or variations of an item. This features allows to efficaciously develop, test and install metadata inside the manufacturing environment.

Q25. How To Get The First 100 Rows From The Flat File Into The Target?

Create one method and claim the sequence in the system, sooner or later call the process in informatica with the help of stored procedure trformation.

Q26. What Is Difference Between Partitioning Of Relational Target And Partitioning Of File Targets?

Partition's may be performed on both relational and flat documents.

Informatica helps following walls

Database partitioning

RoundRobin

Pass-through

Hash-Key partitioning

Key Range partitioning

All those are applicable for relational targets. For flat file simplest database partitioning isn't always applicable.

Informatica helps Navy partitioning. You can just specify the call of the goal file and create the partitions, rest could be taken care via informatica consultation.

Q27. Discuss The Advantages & Disadvantages Of Star & Snowflake Schema?

In a STAR schema there's no relation among any  size tables, whereas in a SNOWFLAKE schema there is a possible relation between the size tables.

In famous person schema there may be no courting among two relational tables. All dimensions are de-normalized and query overall performance is degrades. In this snow flake schema dimensions are normalized. In this SF schema table space is multiplied. Maintenance price is excessive. Query performance is increased.

Q28. How Do You Handle Decimal Places While Importing A Flatfile Into Informatica?

Whilst uploading flat record definition just specify the size for a numeric records type in the mapping, the flat document supply helps only wide variety datatype (no decimal and integer). In the SQ associated with that source may have a records type as decimal for that variety port of the source.

Supply ->wide variety datatype port ->SQ -> decimal datatype. Integer isn't always supported. For this reason decimal is taken care.

Import the sphere as string and then use expression to convert it, in order that we can avoid truncation if decimal places in supply itself.

Q29. How To Join Two Tables Without Using The Joiner Trformation?

Its feasible to sign up for the two or extra tables through the use of supply qualifier. But furnished the tables should have courting.

When you drag and drop the tables you will getting the supply qualifier for every table. Delete all the source qualifiers. Add a not unusual source qualifier for all. Right click on the supply qualifier you will locate EDIT click on it. Click on the houses tab, you will find square query in that you may write your sqls.

You can also do it using Session --- mapping---supply there you have got an option known as User Defined Join there you could write your SQL.

Q30. What Are The Methods For Creating Reusable Trformations?

There  strategies for creating reusable trformations:

Using trformation developer tool.

Converting a non reusable trformation into a reusable trformation in mapping.

Q31. Difference Between Summary Filter And Details Filter?

Summary Filter - we will follow statistics group with the aid of that comprise commonplace values.

Detail Filter - we are able to follow to each and each document in a database.

Q32. What Can We Do To Improve The Performance Of Informatica Aggregator Trformation?

Aggregator performance improves dramatically if statistics are taken care of earlier than passing to the aggregator and "looked after enter" choice underneath aggregator residences is checked. The report set have to be sorted on the ones columns that are utilized in Group By operation.

It is mostly a properly concept to type the file set in database stage e.G. Inside a source qualifier trformation, except there is a danger that already looked after data from source qualifier can once more end up unsorted before achieving aggregator.

Q33. Doubts Regarding Rank Trformation: Can We Do Ranking Using Two Ports? Can We Rank All The Rows Coming From Source, How?

When ETL load the records from source we are able to claim the rank of the incoming facts to skip a rank trformation. We cannot claim  rank on a single source facts. We can do rank the row with the aid of affirming the rank Trformation and maintaining the rank port.

Q34. What Is The Router Trformation?

A Router trformation is much like a Filter trformation due to the fact both trformations permit you to use a circumstance to check data. However, a Filter trformation assessments facts for one condition and drops the rows of records that do not meet the situation. A Router trformation tests data for one or greater conditions and gives you the choice to route rows of facts that do not meet any of the conditions to a default output institution.

If you want to check the equal input facts based on multiple situations, use a Router Trformation in a mapping in place of growing more than one Filter trformations to perform the same task.

Q35. What Is A Code Page?

A code page includes encoding to specify characters in a hard and fast of one or more languages. The code web page is selected based totally on supply of the information. For example if supply contains Japanese text then the code page have to be decided on to help Japanese text.

When a code page is chosen, the program or application for which the code page is about, refers to a specific set of statistics that describes the characters the utility recognizes. This affects the manner that utility stores, gets, and sends man or woman facts.

Q36. How Can You Access The Remote Source Into Your Session?

Relational source : To get right of entry to relational source that's located in a faraway area , you need to configure database connection to the datasource.

FileSource : To access the far off source document you have to configure the FTP connection to the host gadget earlier than you create the consultation.

Heterogeneous : When you're mapping contains a couple of source type, the server supervisor creates a heterogeneous session that presentations supply alternatives for every type.

Q37. How Do I Import Vsam Files From Source To Target. Do I Need A Special Plugin

As some distance my know-how by using the usage of electricity trade tool convert VSAM file to oracle tables then do mapping as normal to the target table.

Q38. How Can You Complete Unrecoverable Sessions?

Under sure circumstances, whilst a session does not entire, you want to truncate the target tables and run the session from the start. Run the consultation from the start when the Informatica Server can't run recuperation or while going for walks recuperation may bring about inconsistent statistics.

If there may be no recovery mode on in session and workflow failed in mid of execution then

Don’t truncate table at once.

If there's huge volume of information is appearing through the load and more than 25% information has loaded then-if same workflow has more than one consultation then check precise session which brought on to be failed and fire the delete command best to delete particular session records which has loaded and replica the session into new workflow and run only that session or dependent others.

Q39. How Can We Partition A Session In Informatica?

The Informatica PowerCenter Partitioning alternative optimizes parallel processing on multiprocessor hardware by means of offering a thread-primarily based architecture and built-in records partitioning.

GUI-primarily based equipment lessen the improvement effort important to create facts partitions and streamline ongoing troubleshooting and overall performance tuning responsibilities, even as making sure information integrity throughout the execution technique. As the quantity of information inside an organisation expands and actual-time demand for facts grows, the PowerCenter Partitioning alternative allows hardware and applications to provide great performance and jointly scale to deal with massive volumes of data and users.

Q40. Explain Use Of Update Strategy Trformation?

To flag supply facts as INSERT, DELETE, UPDATE or REJECT for goal database. Default flag is Insert. This is should for Incremental Data Loading.

This is the important trformation,is used to preserve the records statistics or just most current changes into the target desk.

We can set or flag the information by means of the use of these  stages.

Within a consultation :

When you configure the consultation,you may coach the informatica server to both treat all the data in the equal way.

Within a mapping :

inside a mapping we use replace strategy trformation to flag the statistics like insert,replace,delete or reject.

Q41. How Do We Estimate The Number Of Partitions That A Mapping Really Requires? Is It Dependent On The Machine Configuration?

It depends upon the informatica model we're the usage of. Think if we are using informatica 6 it supports most effective 32 walls in which as informatica 7 helps sixty four partitions.

Q42. What Is The Use Of Incremental Aggregation? Explain Me In Brief With An Example.

Its a consultation choice, when the informatica server plays incremental aggr. It passes new source statistics through the mapping and uses ancient cache data to carry out new aggregation calculations incrementally for performance we can use it.

When the usage of incremental aggregation, you observe captured changes within the source to aggregate calculations in a consultation. If the source adjustments incrementally and you may seize modifications, you may configure the session to procedure the ones adjustments. This lets in the Integration Service to update the target incrementally, in preference to forcing it to method the entire supply and recalculate the equal records each time you run the session.

Q43. If You Want To Create Indexes After The Load Process Which Trformation You Choose?

Its generally not carried out inside the mapping (trformation) level. Its performed in consultation degree. Create a command venture on the way to execute a shell script (if Unix) or another scripts which incorporates the create index command. Use this command project within the workflow after the session or else, You can create it with a publish session command.

Q44. Explain About Informatica Server Architecture?

Informatica server, load managers, facts trfer supervisor, reader, temp server and author are the components of informatica server. First load manager sends a request to the reader if the reader is ready to examine the facts from source and dump into the temp server and facts trfer supervisor manages the burden and it send the request to writer as according to first in first out procedure and writer takes the records from temp server and masses it into the goal.

Q45. How The Informatica Server Increases The Session Performance Through Partitioning The Source?

For a relational sources informatica server creates multiple connections for every partition of a unmarried supply and extracts separate variety of information for every connection.

Informatica server reads more than one walls of a single source concurrently. Similarly for loading additionally informatica server creates more than one connections to the goal and hundreds walls of statistics concurrently.

For XML and file assets, informatica server reads a couple of documents concurrently. For loading the records informatica server creates a separate file for each partition (of a supply report). You can pick out to merge the objectives.

Q46. How Do You Configure Mapping In Informatica?

Import src from database.

Check if target desk already exists in database.

If it exists make sure u delete information from it and import into fashion designer.

Or else create it with create goal wizard.

Now you could drag wished trformations into the workspace.

Use them in keeping with your purpose.

For progressed performance observe those suggestions:-

Use sorter earlier than aggregator

If clear out is used preserve it as near to the supply as possible.

If possible use an additional expression tr earlier than goal to make corrections in future.

Enable looked after input choice if sorter is used before agg tr.

If more filters are wished use router tr.

You could use supply filter alternative of SQ if filter out tr is right now after source.

In case of router if now not wanted do now not join default group to any goal.

Q47. What Is The Default Join That Source Qualifier Provides?

Inner equi join.

Q48. Can You Start A Batches With In A Batch?

You can't. If you need to start batch that resides in a batch, create a new unbiased batch and replica the essential sessions into the new batch.

Q49. What Are The Joiner Caches?

Specifies the listing used to cache master data and the index to those statistics. By default, the cached documents are created in a directory distinct by means of the server variable $PMCacheDir. If you override the directory, make certain the listing exists and includes enough disk space for the cache documents. The directory may be a mapped or hooked up force. There are 2-styles of cache inside the joiner:

Data cache

Index Cache

Q50. What Is Hash Table Informatica?

In hash partitioning, the Informatica Server uses a hash characteristic to organization rows of facts among partitions. The Informatica Server agencies the records primarily based on a partition key.Use hash partitioning when you need the Informatica Server to distribute rows to the partitions with the aid of institution. For example, you want to kind items by way of item ID, however you do now not know how many gadgets have a particular ID variety.