Vito wrote: > I'm recently doing some research with Apache ODE engine. I use Postgresql as its external database, > openjpa as its ORM solution and bitronix as its transaction manager. The ODE workflow engine starts > without any problem. But when I deploy process definition files into the engine, the exception came > out. I paste the error content at the end of this email. > I looked through the source code of org.apache.openjpa.lib.jdbc.DecoratingDataSource, and found that > openjpa is almost definitely to meant to invoke the function of reseting transaction isolation level, > which would be catched by Postgresql and return with an exception. > Does that mean openjpa works poorly with Postgresql? Or who can tell me how to solve this problem. > The error content is below: > org.apache.openjpa.persistence.PersistenceException: Cannot change transaction isolation level in the > middle of a transaction > Caused by: org.postgresql.util.PSQLException: Cannot change transaction isolation level in the middle > of a transaction That makes sense, doesn't it? I don't think there is any database that would allow to change the isolation level in the middle of a transaction. I tested with Oracle: SELECT .... SET TRANSACTION ISOLATION LEVEL SERIALIZABLE; ERROR at line 1: ORA-01453: SET TRANSACTION must be first statement of transaction I think you will have to make sure that the SET TRANSACTION ISOLATION LEVEL statement is the first statement issued in the transaction. Yours, Laurenz Albe -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
