I really no understand why where use Resource.
I do this command (find and grep), and get file in Resource folder:
find . -type f | grep -P '/Resource/'
Basically Catalog use
app/code/core/Mage/Catalog/Model/Resource/Eav/Mysql4
Why not is it?
app/code/core/Mage/Catalog/Model/Mysql4
In a few moments I thought would be that it uses EAV, but not, because Customer use EAV and no such this hierarchy.
Thanks everyone.