hi finion

regarding to your issue i have no problem with your query i could execute it against DB2 express edition
and Mysql 5 ,the only problem that i faced with the query so instead of

StringBuffer incoming = new StringBuffer();
incoming.append("insert into DagEdgeImpl(entryEdgeId) ")
.append("select edge.id ")
.append("from DagEdgeImpl edge ")
.append("where edge.endVertex.higherBits = ? ")
.append("and edge.endVertex.lowerBits = ? ");

it should be like

StringBuffer incoming = new StringBuffer();
incoming.append("insert into DagEdgeImpl(entryEdgeId) ")
.append("select id ")
.append("from DagEdgeImpl edge ")
.append("where endVertex.higherBits = ? ")
.append("and endVertex.lowerBits = ? ");