[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-3762) LockMode.UPGRADE and TABLE_PER_CLASS and PostgreSQL generates usupported SQL

LockMode.UPGRADE and TABLE_PER_CLASS and PostgreSQL generates usupported SQL ---------------------------------------------------------------------------- Key: HHH-3762 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-3762 Project: Hibernate Core Issue Type: Bug Components: core Affects Versions: 3.3.1 Environment: Hibernate 3.3.1.GA, PostgreSQL 8.2, Hibernate-Annotations, Hibernate-EntityManager, Glassfish v2ur2, Windows Vista 64.bit Reporter: Dobes Vandermeer Priority: Minor I created a class called Job and a few subclasses such as SendEmailJob, ProcessSubscriptionsJob, and so on. I set the inheritance type to TABLE_PER_CLASS since the columns in each are quite different. However, the worker that loads and executes the jobs is the same. The worker was trying to use a piece of code like this: @Timeout public void timeout(Timer timer) { session.get(Job.class, (Long)timer.getInfo(), LockMode.UPGRADE); } PostgreSQL returned the following error: org.postgresql.util.PSQLException: ERROR: SELECT FOR UPDATE/SHARE is not allowed with UNION/INTERSECT/EXCEPT The workaround was to lock the object separately, so hibernate only tries to select .. for update from one table: @Timeout public void timeout(Timer timer) { Job job = session.get(Job.class, (Long)timer.getInfo(), LockMode.NONE); session.refresh(job, LockMode.UPGRADE); // Now there's just one table involved } A possible solution to this issue would be for hibernate to do this breakdown automatically when doing a get() on a TABLE_PER_CLASS superclass - i.e. it would ignore LockMode when fetching, but if LockMode is > UPGRADE it would call refresh() with that lock mode on the found object (if any) to lock it. This does introduce an extra SELECT but I can't really think of another solution for this use case.