Experience with JDBC

I got a java.lang.OutOfMemoryError when I used select * this morning, and used Java -Xmx640000000 to realloc heap size to solve it.

When using ResultSet.updateRow() to update records, you must use a statement created this way:
stmt = conn.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_UPDATABLE);
and your table must have a primary key.