If you are working with large documents with extensive metadata or key references, you will need to
    increase the memory allocation for the Java process. You can do this from the command-line prompt for a specific
    session, or you can increase the value of the ANT_OPTS environment variable.
    Procedure
- 
        To change the value for a specific session, from the command prompt, issue the following command:
        
        
          This increases the JVM memory allocation to 1024 megabytes. The amount of memory which can be allocated is
            limited by available system memory and the operating system. 
 
- 
        To persistently change the value, change the value allocated to the ANT_OPTSenvironment
          variable on your system.