Question

If a file consists of 5 attributes, than what is the number of secondary indices that can be constructed on the file?? plz answer n explain the anwer also.. :)

Answer 1

A secondary index provides a secondary means of accessing a data file for which
some primary access already exists. The data file records could be ordered,
unordered, or hashed. The secondary index may be created on a field that is a candidate key and has a unique value in every record, or on a nonkey field with duplicate values.
From -> Navathe DBMS !

So we need to have primary index too. Assuming we used 1 column for that, we have 4 columns remaining, using which we can have max 4 secondary indexes !

Answer 2

secondary index is on unordered attribute . a file with 5 attributes, to find secondary indices on this  based on one remaining will be ordered so there are 4 secondary indices  possible