Considering the scenario depicted in the diagram below, as the title says, can a weak entity type take part in an "is-a" relationship?
When I've modeled databases, I would use a
isType description where you have
isA. You appear to have two types of
itemSpecs. Common data belongs in
Specs entity, with type specific data in the appropriate subtype record. Normally subtypes are exclusive, so a Spec would be either a
labelSpec or an