Getting GC overhead limit exceeded while fetching millions of records using JPA createQuery();

Question

String reportQuery="Select pr from ProductivityReport pr where pr.reportDate=:reportDate";
Query query = entityDao.getEntityManager().createQuery(reportQuery,ProductivityReport.class).setHint("org.hibernate.readOnly", Boolean.TRUE);

Here I am trying to fetch a result on the basis of date where I get

Caused by: java.lang.OutOfMemoryError: GC overhead limit exceeded

As I have went for solution to related sites and the solutions are: To implement ScrollableResults if you wants to fetch millions of records but this method is not defined in Query interface in our product.

To apply pagination, but if I hit ResultList more than once, I'm facing an exception

java.lang.IllegalStateException: Session/EntityManager is closed that is due to session closed.

query.setHint("eclipselink.read-only", "true"); also not working.

Please suggest me an another solution for fetching millions of rows through JPA as I get stuck to those exceptions which in result gives me an unexpected behaviour while generating report i.e. page gets unresponsive.

You're trying to retrieve so many rows that your JavaVM instance runs out of RAM. It isn't a garbage-collector (GC) issue, it's a too-much-data to handle at once issue. You must figure out how to fetch those rows one at a time or in batches, not all at once. — O. Jones, Dec 05 '20 at 22:54

Getting GC overhead limit exceeded while fetching millions of records using JPA createQuery();

0 Answers0