I had quickly queried SELECT COUNT FROM sometable ORDER BY ColA, ColB and received org.teiid.core.TeiidProcessingException: null as a result. Checking the server, I found the stack trace below. Neither actually points out the ORDER BY is incorrect since it does not reference projected columns.

A clearer message will help the users.

2010-12-14 12:54:05,010 ERROR [org.teiid.CONNECTOR] (Worker28_QueryProcessorQueue2669) Connector worker process failed for atomic-request=J76UbF11tQAM.0.1.753
java.lang.AssertionError
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:504)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:432)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:207)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:130)
at org.teiid.dqp.internal.datamgr.ConnectorWorkItem.execute(ConnectorWorkItem.java:213)
at org.teiid.dqp.internal.process.DataTierTupleSource.getResults(DataTierTupleSource.java:281)
at org.teiid.dqp.internal.process.DataTierTupleSource.access$000(DataTierTupleSource.java:71)
at org.teiid.dqp.internal.process.DataTierTupleSource$1.call(DataTierTupleSource.java:123)
at org.teiid.dqp.internal.process.DataTierTupleSource$1.call(DataTierTupleSource.java:120)
at org.teiid.dqp.internal.process.DQPCore$FutureWork.run(DQPCore.java:108)
at org.teiid.dqp.internal.process.DQPWorkContext.runInContext(DQPWorkContext.java:188)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$RunnableWrapper.run(ThreadReuseExecutor.java:116)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$3.run(ThreadReuseExecutor.java:290)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
2010-12-14 12:54:05,042 WARN [org.teiid.PROCESSOR] (Worker27_QueryProcessorQueue2670) Processing exception 'null' for request J76UbF11tQAM.0. Exception type org.teiid.core.TeiidProcessingException thrown from org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:504). Enable more detailed logging to see the entire stacktrace.
2010-12-14 12:54:20,404 ERROR [org.teiid.CONNECTOR] (Worker28_QueryProcessorQueue2673) Connector worker process failed for atomic-request=Tfqv5NFZIOX4.0.1.754
java.lang.AssertionError
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:504)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:432)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:207)
at org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:130)
at org.teiid.dqp.internal.datamgr.ConnectorWorkItem.execute(ConnectorWorkItem.java:213)
at org.teiid.dqp.internal.process.DataTierTupleSource.getResults(DataTierTupleSource.java:281)
at org.teiid.dqp.internal.process.DataTierTupleSource.access$000(DataTierTupleSource.java:71)
at org.teiid.dqp.internal.process.DataTierTupleSource$1.call(DataTierTupleSource.java:123)
at org.teiid.dqp.internal.process.DataTierTupleSource$1.call(DataTierTupleSource.java:120)
at org.teiid.dqp.internal.process.DQPCore$FutureWork.run(DQPCore.java:108)
at org.teiid.dqp.internal.process.DQPWorkContext.runInContext(DQPWorkContext.java:188)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$RunnableWrapper.run(ThreadReuseExecutor.java:116)
at org.teiid.dqp.internal.process.ThreadReuseExecutor$3.run(ThreadReuseExecutor.java:290)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
2010-12-14 12:54:20,405 WARN [org.teiid.PROCESSOR] (Worker27_QueryProcessorQueue2674) Processing exception 'null' for request Tfqv5NFZIOX4.0. Exception type org.teiid.core.TeiidProcessingException thrown from org.teiid.dqp.internal.datamgr.LanguageBridgeFactory.translate(LanguageBridgeFactory.java:504). Enable more detailed logging to see the entire stacktrace.