TCS,Accenture,H.P,Spaninfotech,Infosys,Headstrong Interview Q&A

TCS interview questions 

1.explain  ur project?

2.how to display duplicate records in a table by using sql query?
ex:100 aaa
   100 aaa
   100 aaa
   101 bbb
   102 ccc

i want to dispaly like this 100 aaa
                                     100 aaa
                                     100 aaa

3.explain scd type2 i have the data d1 1 mum
                                                     d2 1 kol
                                                     d3 1 hyd
how it will be inserted?

4.what is mapplet and expalin where u can use mapplet in realtime?

5.emp
  boss
  sales transaction
  hra a/c

in which what are the fact and dimensional tables?

6.explain mapping parameters and variables?

7.what is factless fact table and explain where u can use in realtime?

8.diff b/w in and exist?(sub quaries)

9.i have 100 records in my target table and next day i want to insert 5 records,
and i want to update 10 records then what is tot no.of records in my target table?(by using scd2)

10.diff b/w connected and unconnected lkp?

11.by using which transformation u can capture the rejected records and where it will be stored?

12.what is the shortcut and reusable transformation?

13.in my table 1000 records are there i want to get 100 records what is the sqlquery?

14.diff b/w sourcequalifier and filter?

15.what is abort and stop where we can use abort?

16.what are types of tracing levels and what is the verbose initialization?

17. diff b/w union and joiner?

18. what are the reusable and nonreusabletasks?
                            Accenture
1.whandot is the diff b/w 7.x/8.x?

2.what is the sql transformation and explain?

3.what is domain and node?

4.what is the use of associated port in lkp transformation?

5.what is the diff b/w sql source qualifier and flatfile sourcequalifier?

6.I have 1000 flatfiles i had already loaded 700 flatfiles how to you load remaining 300 flatfiles?

7.i have to load 1 lakh of records to the production system in b/w the session
fail what u can do(u can't restart,and also u r not assiging session to a recovery mode)?

8.how can u migrate the code from developed environment to productionenvironment?

9.which type of scd2 can u use in ur project?

10.if ur source data contain no duplictes and also u don't want to perform incremental agrregation
and no need of sorting the data then what is the use of sorter t/r before aggregator?

11.my parameter file dosen't contain any value then how the integration service executed the parameter file?

12.if ur using mapping variable and run the session if the session fails then what is the value in repository?

13. what are the reusable tasks ur used?

                           Spaninfotech
1.select max(sal),deptno from emp where max(sal)>2000 group by deptno this Query is right or wrong?
Ans:select max(sal),deptno from emp group by deptno having max(sal)>2000 it is the right one.

2. what is the diff b/w where and having clause?
Ans:where can restrict each row or record
having clause restrict group of records.

3.Can we use transaction control transformation on a flatfile target?
Ans:we can't use,Transaction Control transformations connected to any target other than relational, XML, or dynamic MQSeries targets are ineffective for those targets.

4.which one given better performnce static or dynamic lkp?
Ans:Performance wise static lookup is better than dynamic lkp,dynamic Lookup is that they are slow as the caches are updated frequently based on the transaction posted in the database.
5. when we use dynamic lookup?
Ans:if the table contains more no.of duplicate records then we use dynamc lkp to eliminate duplicates.
6.i have 10 records in my source table  i can take  filter transformation i can give the condition true then how many records loaded into the target tale ?
ANs :10 records,every active transaformation by default act as passive transformation.
                                HP Company

1.what is meant by inlineview?
Ans: inline view is a SELECT statement in the FROM-clause of another SELECT statement.
In-line views are commonly used simplify complex queries by removing join operations 
and condensing several separate queries into a single query.

2.what is conformed dimension?
Ans:a dimension table can be shared by more than one facttable is known conformed dmension.
ex:date dimension.

3.what is factlessfact table?
Ans:factless fact table captures many to many relationship b/w dimensions,and it dosen't contain any numeric values.
ex:studance attandence tracking.
store that did not sell a product over aperiod of time.

4.i have 3 flatfiles with same stracture how to join without using joiner transformation?
Ans:by using file list concept with file type as indirect .

5.how to delete the duplicate records in unix?
Ans:sort filename.txt|uniq -u

6.what is surrogatedkey?
Ans:surrogatedkey is a systemgenarated sequence number to be used as a primary key.

7.what is diff b/w surrogatekey and primarykey?
Ans:   surrogatekey                             primarykey
    1.artificialkey                                   1.naturalkey
    2.generated by system sequance       2.generated by database 
       number

8.what is subqurey & corelated subquarey?
Ans:subquarey:-A query nested inside a SELECT statement is known as a subquery 
and is an alternative to complex join statements.
CorelatedsubQuarey:-It is a sub-query (a query nested inside another query) 
that uses values from the outer query in its WHERE clause. The sub-query 
is evaluated once for each row processed by the outer query.


9.how to eliminate duplicate records in informatica and in sql?
Ans:in informatica by using distinct property in sourcequalifier or by using sortet t/r.
in sql delete from emp where rowid not in(select max(rowid) from emp group by empno);
         Infosys Interview questions
 1.Explain u r project architecture?
2.What is staging area and why u r using in ur project?
3.if u have a source system contain records of three months jan,feb,march I want to load the data in to  three targets jan,feb,mar draw the mapping?
4.diff b/w static lkp and dynamic lkp?
5.what is different types of joins in jnr t/r?
6.in filter t/r I can give filter condition to 4 what can happened?
7.In agg t/r I can use sorted input option but I cant pass sorted data what happened?
8.explain normalize t/r give one example how it can convert single input record to multiple o/p records?
9.what is verboseinitialization?

                        HEADSTRONG Interview Quest&Ans
1.How to update records in Target, without using Update Strategy?

YES WITHOUT A pk WE CANT UPDATE THE REC u can write sql query at target
level. in target table properties there is a option update
override.

IN SESSION PROPERTIES WE HAVE ONE OPTION TREAT ALL ROWS
AS... THERE U SELECT UPDATE OPTION AND IN THE TARGET
PROPERTIES SELECT UPDTAE OPTION.

2.Can we lookup a table from source qualifier transformation?
yes we can lookup a table by using S.Q by using sql override.

3.how can we stop batch
By using server manager or pmcmd.

4.Can u start a batches with in a batch?

U can not. If u want to start batch that resides in a batch,create a new independent batch and copy the necessary sessions into the new batch.

5.Can u start a session inside a batch idividually?
We can start our required session only in case of sequential batch.in case of concurrent batch
we cant do like this.
6.how do you connect to remoteserver?
using ftp through telnet/putty/command prompt.
7.What is a command that used to run a batch?
pmcmd is a command line programme. this can be used to stop,run and abort the session.

8.If i done any modifications for my table in back end does it reflect in informatca warehouse or maping desginer or source analyzer?
NO. Informatica is not at all concern with back end database.It displays you all the information  that is to be
stored in repository.If want to reflect back end changes to informatica screens, again you have to import from back end
to informatica by valid connection.And you have to replace the existing files with imported files.

9.How many ways you create ports?
1.Drag the port from another transforamtion
2.Click the add buttion on the ports tab.

10.which is better among incremental load, Normal Load and Bulk load?
It depends on the requirement. Otherwise Incremental load which can be better as it takes only that data which is not available previously on the target.

11.What is the difference between Informatica server, Repository Server and Power center Server ?
Informatica Server and PowerCenter Server both mean the same. It is concerned with running of sessions and workflows.
The Repository Server or the Informatica Rep Server is concerned with connecting to the repository through the Rep Agent.
One Repository Server can connect to many repositories at a time.
For the PowerCenter Server to be up and working it is necessary that the Repository Server is running.

12.in my source table different dateformats i want to load the data into my target single date format how it can be achieved?
by using to_date(datecolumn,'MM/DD/YYYY')

13.while extracting the data from a mainframe sources which transformation should we use?
The mainframe files are Used as VSAM files in Informatica by using the Normaliser transformation

14.i have 7 flatfiles i want to join those files how many joinertransformations required?
6.(n-1)

15.what is pushdownoptimization?
Pushdown optimization is a way of load-balancing among servers in order to achieve optimal performance.
Veteran ETL developers often come across issues when they need to determine the appropriate place to perform ETL logic.
Suppose an ETL logic needs to filter out data based on some condition. One can either do it in database by using WHERE condition
in the SQL query or inside Informatica by using Informatica Filter transformation. Sometimes, we can even "push" some transformation logic
to the target database instead of doing it in the source side (Especially in the case of EL-T rather than ETL).
Such optimization is crucial for overall ETL performance.

16.explain persistance lookupcache?
If the lookup source does not change between sessions, configure the Lookup transformation to use a persistent lookup cache.
The Integration Service then saves and reuses cache files from session to session, eliminating the time required to read the lookup source.

17.i want to send an email, if email task will run only when no data is loaded into the target?
After your session, create an email task. Connect session and email task with the link condition
TgtSuccessRows = 0 and PrevTaskStatus = SUCCEEDED.