4/11/16

Informatica Interview Questions with Answers-1

Question.1 What are the different uses of a repository manager?

Answer: Repository manager used to create repository which contains metadata the informatca uses to transform data to from source to target. And also it use to create inforrnatica user’s and folders and copy, backup and restore tie repository .
Question.2 How do you take care of security using a repository manager?
Answer:   Using repository privileges, folder permission and locking. Repository privileges(Session operator. Use designer, Browse repository, Create session and batches, Administer repository, administer server, super user) Folder permission(owner, groups, users) . Locking(Read, Write, Execute, Fetch, Save) .
Question.3 What is a folder?
Answer:   Folder contains repository objects such as sources, targets, mappings, transformation which are helps logically, organize our data warehouse.
Question.4 Can you create a folder within designer?
Answer:   Not possible
Question.5   What are shortcuts? Where it can tie used? What are the advantages?
Answer:   There are two shortcuts (Local and global) Local used in local repository and global used in global repository. The advantage is reusing an object without creating multiple objects. Say for example a source definition want to use in 10 mappings in 10 different folders without creating 10 multiple source you create 10 shortcuts.
Question.6 how do you increase the performance of mappings?
Answer:   Use single pass read(use one source qualifier instead of multiple SO for same table) Minimize data type conversion (Integer to Decimal again back to Integer) Optimize transformation(when you use Lookup, aggregator, filter, rank and joiner).
  • Use caches for lookup Aggregator use presorted port, increase cache size, minimize input/out port as much as possible Use Filter wherever possible to avoid unnecessary data flow.
Question.7   Explain lnformatica  Architecture?
Answer:   Informatica consist of client and server. Client tools such as Repository -manager, Designer, Server manager. Repository data base contains metadata it read by inforrnatica server used read data from source, transforming and loading into target.
Question.8 What are the constants used in update strategy?
Answer:   OD_INSERT, DD_UPDATE, DD_DELETE, DD REJECT.
Question.9 what is difference between connected and unconnected lookup transformation?
Answer:   Connected lookup return multiple values to other transformation Where as unconnected lookup return one values If lookup condition matches Connected lookup return user defined default values Where as unconnected lookup return null values Connected supports dynamic caches where as unconnected supports static.
Question.10 What you will do in session level for update strategy transformation?
Answer:     In session property sheet set Treat rows as “Data Driven” .
Question.11  What are the port available for update strategy , sequence generator, Lookup, stored procedure transformation?
Answer:
Transformations                                              Port
Update strategy                                            Input, Output
Sequence Generator                                 Output only
Lookup                                                            Input, Output, Lookup, Return
Stored Procedure                                        Input, Output
Question.12 what is an active and passive transformation?
Answer:   Active transformation change the no. of records when passing to targe(example filter) where as passive transformation will not change the transformation(example expression) .
Question.13  What are the tracing level?
Answer:   Normal – It contains only session initialization details and transformation details no. records rejected, applied
Terse – Only initialization details will be there Verbose Initialization — Normal setting information plus detailed information about the transformation.
Verbcse data — Verbose in it. Settings and all information about the session .
Question.14   How will you make records in groups?
Answer:   Using group by port in aggregator .
Question.15 Need to store value like 145 into target when you use aggregator, how will you do that?
Answer:   Use Round() function
Question.16 How will you move mappings from development to production database?
Answer:   Copy all the mapping from development repository and paste production repository while paste it will prompt whether you want replace/rename. If say replace informatica replace all the source tables with repository database.
Question.17  What is difference between aggregator and expression?
Answer: Aggregator is active transformation and expression is passive transformation Aggregator transformation used to perform aggregate calculation on group of records really Where as expression used perform calculation with single record.
Question.18 What are Router transformation?
Answer:   Router transformation is an Active and Connected transformation. It is similar to filter transformation. The only difference is, filter transformation drops the data that do not meet the condition whereas router has an option to capture the data that do not meet the condition. It is useful to test multiple conditions.
Question.19  What are Sorter transformation?
Answer:   Sorter transformation is a Connected and an Active transformation. It allows to sort data either in ascending or descending order according to a specified field.