Re:PostgreSQL 9.3 Beta 1 Released
by zapov on Monday May 13, 2013 @10:53AM
(#5698980)
Postgres supports native nested structures. Well, as long as your structures are not circular.
JSON everywhere is really a bad choice for most data structures. It's like having no structure at all.
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Which is pretty much what you want to build a schemaless nosql-on-postgres.
Also, Posgres already has hstore (already mentioned) and XML columns, which are schemaless and "unstructured".