On 28th of January, Andrew Dunstan committed patch:
New json functions. json_build_array() and json_build_object allow for the construction of arbitrarily complex json trees. json_object() turns a one or two dimensional array, or two separate arrays, into a json_object of name/value pairs, similarly to the hstore() function. json_object_agg() aggregates its two arguments into a single json object as name value pairs. Catalog version bumped. Andrew Dunstan, reviewed by Marko Tiikkaja.