Re: [PATCH] Generalized JSON output functions

On Thu, May 21, 2015 at 2:23 AM, Shulgin, Oleksandr

<oleksandr.shulgin@zalando.de> wrote:
> On Wed, May 20, 2015 at 4:06 PM, Merlin Moncure <mmoncure@gmail.com> wrote:
>>
>> On Wed, May 20, 2015 at 8:16 AM, Shulgin, Oleksandr
>> <oleksandr.shulgin@zalando.de> wrote:
>> >
>> > a) no spaces
>> >
>> > select to_json(row(1,2));
>> >      to_json
>> > -----------------
>> >  {"f1":1,"f2":2}
>> >
>> > b) some spaces (hstore_to_json)
>> >
>> > select hstore(row(1,2))::json;
>> >          hstore
>> > ------------------------
>> >  {"f1": "1", "f2": "2"}
>> >
>> > c) spaces around colon
>> >
>> > select json_build_object('f1',1,'f2',2);
>> >   json_build_object
>> > ----------------------
>> >  {"f1" : 1, "f2" : 2}
>> >
>> > d) spaces around colon *and* curly braces
>> >
>> > select json_object_agg(x,x) from unnest('{1,2}'::int[]) x;
>> >    json_object_agg
>> > ----------------------
>> >  { "1" : 1, "2" : 2 }
>> >
>> > e) line feeds (row_to_json_pretty)
>> >
>> > select row_to_json(row(1,2), true) as row;
>> >    row
>> > ----------
>> >  {"f1":1,+
>> >   "f2":2}
>> >
>> > Personally, I think we should stick to (b), however that would break a
>> > lot
>> > of test cases that already depend on (a).  I've tried hard to minimize
>> > the
>> > amount of changes in expected/json.out, but it is quickly becomes
>> > cumbersome
>> > trying to support all of the above formats.  So I've altered (c) and (d)
>> > to
>> > look like (b), naturally only whitespace was affected.
>>
>> Disagree.  IMNSHO, the default should be (a), as it's the most compact
>> format and therefore the fastest.  Whitespace injection should be
>> reserved for prettification functions.
>
>
> I have no strong opinion on choosing (a) over (b), just wanted to make the
> change minimally sensible.  If at all, I think we should modify existing
> code to make JSON output consistent: that is choose one format an stick to
> it.

sure -- did you mean to respond off-list?

anyways, inserting spacing
into the serialization function formatting (xx_to_json) for me will
raise memory profile of output json by 10%+ in nearly all cases.   I
just don't see the benefit of doing that given that the json is still
not very 'pretty'.