how to handle result set data

Question

Hello All

I am getting lot of records in my Result Set. My concerns are :

1. How Result Set handle these records internally? and
2. How a programmer can handle those records in batches So that memory problem would not occur.?

waiting for your answers .. Many Thanks

Answer 1

You can use Statement.setFetchSize() to control the number of records fetched into memory when you iterate through result set. But in general I think it depends on JDBC driver on how it handles that setting and how it stores fetched records in memory.

EDIT: Here is an example (in theory result set will keep only 1 records in memory):

Statement stmt = con.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.FETCH_FORWARD);
stmt.setFetchSize(1);
ResultSet srs = stmt.executeQuery("SELECT COF_NAME, PRICE FROM COFFEES");
while (srs.next()) {
   String name = srs.getString("COF_NAME");
   float price = srs.getFloat("PRICE");
   // Do your processing...
}