Getting Java heap space error

[Praveen Ramachandran]

The code snippet is like this:

Session session = HiberUtil.getSession();
String queryAmmend0 = "from com.hib.Phase1And2CisgiAmendIdBean " +" as obj where obj.processFlag ='Phase2'and obj.status = 'C' ORDER BY obj.invoiceNumber ASC ";
Query query=session.createQuery(queryAmmend0);
List<Phase1And2CisgiAmendIdBean> listAmmend0 =query.list();

Here the query is fetching more than 8 lakh records and when trying to add to the list(listAmmend0) the java heap space error is triggered......

Can anyone there help me out on this.Thanks in Advance!!!

[venkat nadikattu]

Set the following to increate the heap size
-Xms5M -Xmx1024M

[Rob Spoor]

The -Xms5M will not be necessary, but it can help. The other one sets the maximum amount of memory Java can use (from 64MB) to 1024MB. Never forget the M though, or you will have only 1024 bytes!

[Praveen Ramachandran]

I am still getting the heap space after trying the fix you have mentioned ..Anywaz thanks for the effort!!

[Ramya Chowdary]

You are fetching 800K Record, and your driver load them into memory causing outofmemory Exception.

Try this, Use limit clause of sql, bring bunch by bunch

Or

more elegant solution,(Assuming your Database and its driver supports Scrolling, and also its better to use jdbc:mysql://localhost/semanticdb?useCursorFetch=true) Mysql 5.X supports Scrolling

 fullTextSession.setFlushMode(FlushMode.MANUAL);
        fullTextSession.setCacheMode(CacheMode.IGNORE);
        ScrollableResults results = fullTextSession.createCriteria( "UR CRITERIA" )
        .setFetchSize(500000)
        .scroll( ScrollMode.FORWARD_ONLY );


        while(results.next()) {
        }