fixed bug 3403, ie check for NULL's on the real column not only on the persistent column part (ie not looking at deletes and updates).
fixed bug 3403, ie check for NULL's on the real column not only on the
persistent column part (ie not looking at deletes and updates).

zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb,zyzyis/monetdb