SQL & PL/SQL

I am firing a query which is returning a large no. of records(> 2 M). It contains data in the col's as :

Empid, name, sal, dept.......etc.

I am calling this query from a java program.
Here I need all the Empid's returned by the query for the first time.
Then I will split these Empid's into equal no. of groups (100 id's - 1 group).
So... for each group I need all col's data for the 100 Empid's in each group.

My question is : In the first hit any how I am getting all data. After that, for each group rather than hitting DB again and again from getting remaining col's data, is there any way of storing the data somewhere, So that I can get the remaing col's data for each group from there.