How to avoid OOM (Out of memory) error when retrieving all records from huge table?
With a little more information I can get a more helpful answer.
If you are using MySQL:
stmt = conn.createStatement(java.sql.ResultSet.TYPE_FORWARD_ONLY, java.sql.ResultSet.CONCUR_READ_ONLY);stmt.setFetchSize(Integer.MIN_VALUE);from http://www.oracle.com/technology/tech/java/sqlj_jdbc/htdocs/jdbc_faq.html:
java.util.Properties info = new java.util.Properties();info.put ("user", "scott");info.put ("password","tiger");info.put ("defaultRowPrefetch","15");getConnection ("jdbc:oracle:oci:@",info);
If you are using JDBC you can use a ResultSet with a cursor which you iterate through one record at a time. You need to makes sure then that you write your XML out to a file one record at a time rather than using DOM to build the XML.