We have recently had a situation where our application has failed to handle a DB crash.
When the DB restarted, the process successfully reconnected but kept having the following error (in the stack trace below) whenener it attepted to load/find objects from a join (eager fetch across objects). So it could do selects fine, but looked to be having trouble when using joins that used prepared statements.

we resolved the issue by restarting the application. Which is not ideal.

is there away for jdbc/hibernate to refresh its prepared statements, or recreate them ? I suspect we will have the same issue whenever we apply table changes that affect the joined tables as well.

javax.persistence.PersistenceException: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.ejb.AbstractEntityManagerImpl.throwPersistenceException(AbstractEntityManagerImpl.java:614)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:76)
at com.jpmorgan.wss.dm.dao.refdata.impl.xxx.findAPJJobScheduleRunsDone(xxxxxx.java:104)
at com.jpmorgan.wss.hummer.batch.xxx.processSuccessfullFilesInternal(xxxx.java:195)
at com.jpmorgan.wss.hummer.batch.xxx.processSuccessfullFiles(xxxxxx.java:98)
at sun.reflect.GeneratedMethodAccessor881.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:309)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:183)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:150)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:172)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:202)
at $Proxy113.processSuccessfullFiles(Unknown Source)
at sun.reflect.GeneratedMethodAccessor880.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.springframework.util.MethodInvoker.invoke(MethodInvoker.java:273)
at org.springframework.scheduling.support.MethodInvokingRunnable.run(MethodInvokingRunnable.java:65)
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:51)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureTask.java:317)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:150)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$101(ScheduledThreadPoolExecutor.java:98)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.runPeriodic(ScheduledThreadPoolExecutor.java:181)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:205)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:885)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:907)
at java.lang.Thread.run(Thread.java:619)
Caused by: org.hibernate.exception.SQLGrammarException: could not execute query
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:90)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
at org.hibernate.loader.Loader.doList(Loader.java:2235)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2129)
at org.hibernate.loader.Loader.list(Loader.java:2124)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:401)
at org.hibernate.hql.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:363)
at org.hibernate.engine.query.HQLQueryPlan.performList(HQLQueryPlan.java:196)
at org.hibernate.impl.SessionImpl.list(SessionImpl.java:1149)
at org.hibernate.impl.QueryImpl.list(QueryImpl.java:102)
at org.hibernate.ejb.QueryImpl.getResultList(QueryImpl.java:67)
... 28 more
Caused by: com.sybase.jdbc3.jdbc.SybSQLException: user.xxx not found. Specify owner.objectname or use sp_help to check whether the object exists (sp_help may produce lots of output).

at com.sybase.jdbc3.tds.Tds.a(Unknown Source)
at com.sybase.jdbc3.tds.Tds.nextResult(Unknown Source)
at com.sybase.jdbc3.jdbc.ResultGetter.nextResult(Unknown Source)
at com.sybase.jdbc3.jdbc.SybStatement.nextResult(Unknown Source)
at com.sybase.jdbc3.jdbc.SybStatement.nextResult(Unknown Source)
at com.sybase.jdbc3.jdbc.SybStatement.queryLoop(Unknown Source)
at com.sybase.jdbc3.jdbc.SybStatement.executeQuery(Unknown Source)
at com.sybase.jdbc3.jdbc.SybPreparedStatement.executeQuery(Unknown Source)
at org.apache.commons.dbcp.DelegatingPreparedStatement.executeQuery(DelegatingPreparedStatement.java:93)
at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208)
at org.hibernate.loader.Loader.getResultSet(Loader.java:1812)
at org.hibernate.loader.Loader.doQuery(Loader.java:697)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259)
at org.hibernate.loader.Loader.doList(Loader.java:2232)
... 36 more

There's not much hibernate con do about this. Try using a better JDBC driver, like http://jtds.sourceforge.net/