<bpelFault>  
  <faultType>0</faultType>  
  <subLanguageExecutionFault xmlns="http://docs.oasis-open.org/wsbpel/2.0/process/executable">  
   <part name="summary">  
    <summary>An error occurs while processing the XPath expression; the  
         expression is oraext:query-database("select  
         max(salary) from employee",false(),false(),'jdbc/examplesDS').</summary>  
   </part>  
   <part name="detail">  
    <detail>XPath expression failed to execute. An error occurs while  
        processing the XPath expression; the expression is  
        oraext:query-database("select max(salary) from  
        employee",false(),false(),'jdbc/examplesDS'). The XPath  
        expression failed to execute; the reason was: internal xpath  
        error. Check the detailed root cause described in the exception  
        message text and verify that the XPath query is correct.</detail>  
   </part>  
   <part name="code">  
    <code>XPath expression failed to execute</code>  
   </part>  
  </subLanguageExecutionFault>  
 </bpelFault>  

 oracle.xml.sql.OracleXMLSQLException: Character ')' is not allowed in an XML tag name.  
     at oracle.xml.sql.core.OracleXMLConvert.getXML(OracleXMLConvert.java:1178)  
     at oracle.xml.sql.query.OracleXMLQuery.getXMLDOM(OracleXMLQuery.java:417)  
     at oracle.xml.sql.query.OracleXMLQuery.getXMLDOM(OracleXMLQuery.java:384)  
     at oracle.xml.sql.query.OracleXMLQuery.getXMLDOM(OracleXMLQuery.java:345)  
     at oracle.tip.pc.services.functions.ExtFunc.queryDatabase(ExtFunc.java:152)  
     at oracle.tip.pc.services.functions.ExtFuncFunction$QueryDatabaseFunction.call(ExtFuncFunction.java:359)
     ...

 oraext:query-database("select max(salary) as salary from employee",
                                       false(),false(),'jdbc/examplesDS')