Interview Questions

SPAN INFOTECH Interview Questions & Answers

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 Informatica interview Questions and answers

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);