OutOfMemoryError while trying to read a huge table

Question

I do a simple thing like
SELECT id, name FROM myHugeTable ORDER by name
without any WHERE clause since I need to process the whole table somehow and get an OutOfMemoryError.
I see no reason for it, as I do not need all the data at once, so I would expect JDBC to give it to me one row after the other. I need no specials (no updates of ResultSet, no backward going, just rs.next() and simple reading), what should I do?

Answer 1

Hope this helps:
The sql statement gets all the information from the table in a resultSet at once. It doesn't send a separate sql statement to the database each time you get an item out of the resultSet. YOu can get part of the table at a time, process it, then get the rest of the data. For example, processing the names that begin with A first, then those beginning with B, etc:
SELECT id, name FROM myHugeTable where name like 'A%' or 'a%' ORDER by name
SELECT id, name FROM myHugeTable where name like 'B%' or 'b%' ORDER by name
Also, check to ensure your computer has enough memory (at least 1Gbyte, with 2GBytes better). To check into this:
Go to <properties><advanced><enviornment variables> and add the following enviornment variable:
JAVA_OPTS -Xmx1024m
This should allow your JVM to use up a lot more memory (assuming your machine has 1Gbytes of memory).
Are you running tomcat from within Eclipse when this happens? If so, in Eclipse, from the menu go to <window><preferences><tomcat><jvm settings><append to jvm parameters><add> and enter -Xmx1024m
Next, on your desktop, try <cntr><alt><del> <task manager> <performance> and see how much memory you are using with your IDE running before you run your application, then after you run it. Buy more memory if you need it (its cheap!!!). You probably should have at least 2 Gigabtyes. Wouldn't hurt to defragment your hard disk at this time too.