informatica

Top of Form

m

e

techtiks.c om Google Search

54393

1

ISO-8859-1

ISO-8859-1

active

Bottom of Form

ur homepage

Informatica >> Interview Questions

matica

Informatica Repository Manager Q. Q. Q. Q.

Guide

ode

What type of repositories can be created using Informatica Repository Manager? What is a code page? Which all databases PowerCenter Server on Windows can connect to? Which all databases PowerCenter Server on UNIX can connect to?

Informatica Designer

e Tuning

uestions

Board

g

GALT:#008000;G en

new

t Blog

new

Q. Q. Q. Q. Q. Q. Q. Q. Q. Q. Q. Q. Q.

How to execute PL/SQL script from Informatica mapping? How can you define a transformation? What are different types of transformations available in Inform What is a source qualifier? What is meant by Query Override? What is aggregator transformation? What is Incremental Aggregation? How Union Transformation is used? Can two flat files be joined with Joiner Transformation? What is a look up transformation? Can a lookup be done on Flat Files? What are Connected and Unconnected Lookups? What is a mapplet? What does reusable transformation mean? What is update strategy and what are the options for update strategy?

Informatica Repository Manager Q. What type of repositories can be created using Informatica Repository Manager? A. Informatica PowerCenter includeds following type of repositories : •

Standalone Repository : A repository that functions individually and this is unrelated to any othe repositories.

•

Global Repository : This is a centralized repository in a domain. This repository can contain share across the repositories in a domain. The objects are shared through global shortcuts.

•

Local Repository : Local repository is within a domain and it’s not a global repository. Local repos connect to a global repository using global shortcuts and can use objects in it’s shared folders.

•

Versioned Repository : This can either be local or global repository but it allows version control fo repository. A versioned repository can store multiple copies, or versions of an object. This featur

efficiently develop, test and deploy metadata in the production environment. Q. What is a code page?

A. A code page contains encoding to specify characters in a set of one or more languages. The code pag selected based on source of the data. For example if source contains Japanese text then the code page selected to support Japanese text.

When a code page is chosen, the program or application for which the code page is set, refers to a spec data that describes the characters the application recognizes. This influences the way that application s receives, and sends character data. Q. Which all databases PowerCenter Server on Windows can connect to? A. PowerCenter Server on Windows can connect to following databases: •

IBM DB2

•

Informix

•

Microsoft Access

•

Microsoft Excel

•

Microsoft SQL Server

•

Oracle

•

Sybase

•

Teradata

Q. Which all databases PowerCenter Server on UNIX can connect to? A. PowerCenter Server on UNIX can connect to following databases: •

IBM DB2

•

Informix

•

Oracle

•

Sybase

•

Teradata

Infomratica Mapping Designer Q. How to execute PL/SQL script from Informatica mapping?

A. Stored Procedure (SP) transformation can be used to execute PL/SQL Scripts. In SP Transformation PL procedure name can be specified. Whenever the session is executed, the session will call the pl/sql proc

Q. How can you define a transformation? What are different types of transformations availa Informatica?

A. A transformation is a repository object that generates, modifies, or passes data. The Designer provid transformations that perform specific functions. For example, an Aggregator transformation performs ca on groups of data. Below are the various transformations available in Informatica: •

Aggregator

•

Application Source Qualifier

•

Custom

•

Expression

•

External Procedure

•

Filter

•

Input

•

Joiner

•

Lookup

•

Normalizer

•

Output

•

Rank

•

Router

•

Sequence Generator

•

Sorter

•

Source Qualifier

•

Stored Procedure

•

Transaction Control

•

Union

•

Update Strategy

•

XML Generator

•

XML Parser

•

XML Source Qualifier

Q. What is a source qualifier? What is meant by Query Override?

A. Source Qualifier represents the rows that the PowerCenter Server reads from a relational or flat file s it runs a session. When a relational or a flat file source definition is added to a mapping, it is connected Qualifier transformation.

PowerCenter Server generates a query for each Source Qualifier Transformation whenever it runs the se default query is SELET statement containing all the source columns. Source Qualifier has capability to o default query by changing the default settings of the transformation properties. The list of selected port order they appear in the default query should not be changed in overridden query. Q. What is aggregator transformation?

A. The Aggregator transformation allows performing aggregate calculations, such as averages and sum Expression Transformation, the Aggregator transformation can only be used to perform calculations on Expression transformation permits calculations on a row-by-row basis only.

Aggregator Transformation contains group by ports that indicate how to group the data. While grouping the aggregator transformation outputs the last row of each group unless otherwise specified in the tran properties. Various group by functions available in Informatica are : AVG, COUNT, FIRST, LAST, MAX, MEDIAN, MIN, PERCENTILE, STDDEV, SUM, VARIANCE. Q. What is Incremental Aggregation?

A. Whenever a session is created for a mapping Aggregate Transformation, the session option for Increm Aggregation can be enabled. When PowerCenter performs incremental aggregation, it passes new sour through the mapping and uses historical cache data to perform new aggregation calculations incremen Q. How Union Transformation is used?

A. The union transformation is a multiple input group transformation that can be used to merge data fro sources (or pipelines). This transformation works just like UNION ALL statement in SQL, that is used to c result set of two SELECT statements. Q. Can two flat files be joined with Joiner Transformation?

A. Yes, joiner transformation can be used to join data from two flat file sources. Q. What is a look up transformation?

A. This transformation is used to lookup data in a flat file or a relational table, view or synonym. It comp transformation ports (input ports) to the source column values based on the lookup condition. Later retu values can be passed to other transformations. Q. Can a lookup be done on Flat Files? A. Yes. Q. What is the difference between a connected look up and unconnected look up? A. Connected lookup takes input values directly from other transformations in the pipleline.

Unconnected lookup doesn’t take inputs directly from any other transformation, but it can be used in an transformation (like expression) and can be invoked as a function using :LKP expression. So, an unconn lookup can be called multiple times in a mapping. Q. What is a mapplet? A. A mapplet is a reusable object that is created using mapplet designer. The mapplet contains set of transformations and it allows us to reuse that transformation logic in multiple mappings. Q. What does reusable transformation mean?

A. Reusable transformations can be used multiple times in a mapping. The reusable transformation is st metadata separate from any other mapping that uses the transformation. Whenever any changes to a r transformation are made, all the mappings where the transformation is used will be invalidated. Q. What is update strategy and what are the options for update strategy?

A. Informatica processes the source data row-by-row. By default every row is marked to be inserted in t table. If the row has to be updated/inserted based on some logic Update Strategy transformation is use condition can be specified in Update Strategy to mark the processed row for update or insert. Following options are available for update strategy : •

DD_INSERT : If this is used the Update Strategy flags the row for insertion. Equivalent numeric va DD_INSERT is 0.

•

DD_UPDATE : If this is used the Update Strategy flags the row for update. Equivalent numeric va DD_UPDATE is 1.

•

DD_DELETE : If this is used the Update Strategy flags the row for deletion. Equivalent numeric va DD_DELETE is 2.

•

DD_REJECT : If this is used the Update Strategy flags the row for rejection. Equivalent numeric va DD_REJECT is 3.

• RE: What is aggregate cache in aggregator transforamti...

Aggregate cache contains data values while aggregate calculations are being performed. Aggregate cache is made cache and data cache. Index cache contains group values and data cache consists of row values.

RE: What is aggregate cache in aggregator transforamti...

when server runs the session with aggregate transformation it stores data in memory until it completes the agg when u partition a source the server creates one memory cache and one disk cache for each partition .it routes th one partition to another based on group key values of the transformation