Post-relational databases and Entity-Attribute-Value model

r937 · #1 (**permalink**) 03-23-06, 18:23

COMMENTARY: Introduction to Dynamic Data Models in Healthcare

tony, i thought you'd like to see that because of the EAV

and was that really you who suggested this table:

Code:

person_name  item_type  item_name
-----------  ---------  ---------
eric         book       book1
eric         book       book2
eric         song       song2
...

that looks an awful lot like an extensible "type/value" structure to me, eh

andrewst · #2 (**permalink**) 03-24-06, 07:59

Quote:

Originally Posted by r937

that looks an awful lot like an extensible "type/value" structure to me, eh

Yes, I did realise that even as I posted it! But I would argue that it is more of a supertype/subtype design that an EAV model really!

I don't know what it is about the Healthcare and Pharmaceutical world that it seems to find EAV so beguiling. I mean, is it that they actually face a different situation from the rest of us where full-on flexibility is paramount, or is it just a culture thing - i.e. all the database designers in that industry pick up the EAV idea from each other like a, er, virus...?