Christian Beikov Can you please verify that you have this the correct way? I am seeing an awful lot of resources out on the web that say DB2 support is exactly the opposite of what you say. Namely, that the valid combos are:

• ASC + NULLS FIRST
• DESC + NULLS LAST

Also, in terms of the portability concern, I am tempted to do what I suggested here: https://hibernate.atlassian.net/browse/HHH-465?focusedCommentId=34450&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-34450

Basically for DB2, the accepted combo is pointless as it does not effect the query results. So (imo) we should simply drop the NULLS FIRST/LAST when it is an accepted combo by DB2 and when it is not an accepted combo we should inject the CASE statement...