[clarkdave]

Indeed! There is at least one other difference, which is that the presence of null characters will cause an error in `jsonb`, but not `json`:

# select '{ "id": "\u0000" }'::json;

-> { "id": "\u0000" }

# select '{ "id": "\u0000" }'::jsonb;

-> ERROR: unsupported Unicode escape sequence

[cryptonector]

The object key order thing is not a JSON spec compliance issue, but this one is. Either PG should store this escaped or use counted byte strings, but you can see why neither is desirable for a high-performance binary JSON format.