You’re pretty close, but SD’s don’t allow you to create tables in the way you describe. You can’t GET all the SD’s of a certain type with a single API call, you have to ask for a SD with a specific identifier. The address of an SD object in the SAFE distributed hash table is SHA512(tag_type + identifier). The way my protocol create “links” between SD objects uploaded by different people is by describing how the identifier of a new SD object is derived from the address of an existing (parent) SD object. By knowing the parent SD address, all the child SD addresses can be recursively computed and retreived by anyone that has an implementation of the protocol. Think of it as a tree of SD objects, with the root being a website, forum category, or even a SAFE public ID.
I’ll explain it better in the near future, no worries 
The SAFE Network won’t be able to do distributed computing initially, so the farmers won’t be executing the code of that server software.
@19eddyjohn75 Thanks for the suggestions, that’s definitely food for thought.