Tapas

I don't think that will work because your query is based on the row number and not the value of the salary column. It's the 2nd highest salary, not the row with the 2nd highest rownumber.

In general for a relational database queries involving physical aspects of the table (like rownum) should be avoided.  The relational model is based on comparing values that represent facts about things in the real world, not facts about the internal makeup of tables rows and columns.