What do you do with the documents? Join them? Search them? Filter them? Summarize/aggregate them? All of the above? Do you have schemas for them? (Just curious!)
These documents are simply sent to our client apps. All the processing happens on MySQL. And since we are sending JSON, so instead of creating JSON on runtime, we store as a document and retrieve that and send to the client.
We retrieve documents using the unique id generated in mysql table.