Set function parameter names and defaults. Add jsonb versions (which the
code already provided for so the actual new code is trivial). Add jsonb
regression tests and docs.
Bump catalog version (which I apparently forgot to do when jsonb was
committed).
The new format accepts exactly the same data as the json type. However, it is
stored in a format that does not require reparsing the orgiginal text in order
to process it, making it much more suitable for indexing and other operations.
Insignificant whitespace is discarded, and the order of object keys is not
preserved. Neither are duplicate object keys kept - the later value for a given
key is the only one stored.
The new type has all the functions and operators that the json type has,
with the exception of the json generation functions (to_json, json_agg etc.)
and with identical semantics. In addition, there are operator classes for
hash and btree indexing, and two classes for GIN indexing, that have no
equivalent in the json type.
This feature grew out of previous work by Oleg Bartunov and Teodor Sigaev, which
was intended to provide similar facilities to a nested hstore type, but which
in the end proved to have some significant compatibility issues.
Authors: Oleg Bartunov, Teodor Sigaev, Peter Geoghegan and Andrew Dunstan.
Review: Andres Freund
json_to_record() depends on get_call_result_type() for the tuple
descriptor of the record that should be returned, but in some cases
that cannot be determined. Add a guard to check if the tuple
descriptor has been properly resolved, similar to other callers of
get_call_result_type().
Also add guard for two other callers of get_call_result_type() in
jsonfuncs.c. Although json_to_record() is the only actual bug, it's a
good idea to follow convention.
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.
The new JSON API uses a bit of an unusual typedef scheme, where for
example OkeysState is a pointer to okeysState. And that's not applied
consistently either. Change that to the more usual PostgreSQL style
where struct typedefs are upper case, and use pointers explicitly.
The JSON parser is converted into a recursive descent parser, and
exposed for use by other modules such as extensions. The API provides
hooks for all the significant parser event such as the beginning and end
of objects and arrays, and providing functions to handle these hooks
allows for fairly simple construction of a wide variety of JSON
processing functions. A set of new basic processing functions and
operators is also added, which use this API, including operations to
extract array elements, object fields, get the length of arrays and the
set of keys of a field, deconstruct an object into a set of key/value
pairs, and create records from JSON objects and arrays of objects.
Catalog version bumped.
Andrew Dunstan, with some documentation assistance from Merlin Moncure.
Tom Lane