Something along lines of p4 changelist 35761 would be
more helpful than the current exception message.  Without
this change, the exception message simply says
"unknown value in expression:  sortKey" (or something like
that).

With the change applied, the message is

Root cause: 
com.redhat.persistence.engine.rdbms.QGen$5: unknown value in expression: sortKey
query signature: com.arsdigita.categorization.Category(id, objectType,
displayName, defaultDomainClass, description, name, url, isEnabled, isAbstract,
defaultAncestors)
	at com.redhat.persistence.engine.rdbms.QGen$4.map(QGen.java:652)
	at com.redhat.persistence.common.SQLParser.identifier(SQLParser.java:770)


The enumeration of valid values helps pinpoint the error
much more quickly.