Hp interview Questions and answers (11-06-2011)

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);