Horton

Re: Emitting JSON to file using COPY TO

Joe Conway <mail@joeconway.com>

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From: Joe Conway <mail@joeconway.com>
To: Nathan Bossart <nathandbossart@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>
Cc: Andrew Dunstan <andrew@dunslane.net>, Davin Shearer <davin@apache.org>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2023-12-06T19:48:52Z
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 12/6/23 11:44, Nathan Bossart wrote:
> On Wed, Dec 06, 2023 at 10:33:49AM -0600, Nathan Bossart wrote:
>> 	(format csv)
>> 	Time: 12295.480 ms (00:12.295)
>> 	Time: 12311.059 ms (00:12.311)
>> 	Time: 12305.469 ms (00:12.305)
>> 
>> 	(format json)
>> 	Time: 24568.621 ms (00:24.569)
>> 	Time: 23756.234 ms (00:23.756)
>> 	Time: 24265.730 ms (00:24.266)
> 
> I should also note that the json output is 85% larger than the csv output.

I'll see if I can add some caching to composite_to_json(), but based on 
the relative data size it does not sound like there is much performance 
left on the table to go after, no?

-- 
Joe Conway
PostgreSQL Contributors Team
RDS Open Source Databases
Amazon Web Services: https://aws.amazon.com