Re: Emitting JSON to file using COPY TO

Andrew Dunstan <andrew@dunslane.net>

From: Andrew Dunstan <andrew@dunslane.net>
To: Joe Conway <mail@joeconway.com>, Davin Shearer <davin@apache.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-12-06T12:36:36Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →
  1. Add option force_array for COPY JSON FORMAT

  2. json format for COPY TO

  3. introduce CopyFormat, refactor CopyFormatOptions

  4. Doc: add IDs to copy.sgml's <varlistentry> and <refsect1>

On 2023-12-05 Tu 16:46, Joe Conway wrote:
> On 12/5/23 16:20, Andrew Dunstan wrote:
>> On 2023-12-05 Tu 16:09, Joe Conway wrote:
>>> On 12/5/23 16:02, Joe Conway wrote:
>>>> On 12/5/23 15:55, Andrew Dunstan wrote:
>>>>> and in any other case (e.g. LINES) I can't see why you
>>>>> would have them.
>>>
>>> Oh I didn't address this -- I saw examples in the interwebs of MSSQL 
>>> server I think [1] which had the non-array with commas import and 
>>> export style. It was not that tough to support and the code as 
>>> written already does it, so why not?
>>
>> That seems quite absurd, TBH. I know we've catered for some absurdity in
>> the CSV code (much of it down to me), so maybe we need to be liberal in
>> what we accept here too. IMNSHO, we should produce either a single JSON
>> document (the ARRAY case) or a series of JSON documents, one per row
>> (the LINES case).
>
>
> So your preference would be to not allow the non-array-with-commas 
> case but if/when we implement COPY FROM we would accept that format? 
> As in Postel'a law ("be conservative in what you do, be liberal in 
> what you accept from others")?


Yes, I think so.


cheers


andrew

--
Andrew Dunstan
EDB: https://www.enterprisedb.com