This is a forum entry to report a possible bug in JBPM 3.1.4, Oracle (not sure about others) DB scripts.
System: JBossAS 4.0.5 GA + jBPM 3.1.4 GA + RHEL 4 + Oracle 10g.
The column JBPM_VARIABLEINSTANCE.STRINGVALUE_ is slated as VARCHAR2(255 char) while JBPM_LOG.OLDSTRINGVALUE_ and JBPM.NEWSTRINGVALUE_ are slated as VARCHAR2(4000).
These two values should be a match between each other.
Change the DB script for JBPM_VARIABLEINSTANCE, field STRINGVALUE_, from VARCHAR2(255 char) to VARCHAR2(4000 char).