[stopthemadness]

Traditional databases use complicated indexing and storage structures in part to minimize the need to examine unrelated data. hstore is better than plain text for JSON but a scheme closer to the existing PostgreSQL table/page/row/value hierarchy could be better still.

I'd recommend reading the recent post https://news.ycombinator.com/item?id=6813937

[JonnieCache]

Of course if I need it to be eye-wateringly fast I wouldn't be using a document store. I'd use good old relational or something like redis. Often though you just need a sensible place to put some unimportant schemaless key-value data without a half dozen extra dynamically created tables or whatever. EAV makes me very sad.