public inbox for [email protected]  
help / color / mirror / Atom feed
From: Tom Lane <[email protected]>
To: Andrew Dunstan <[email protected]>
Cc: Joe Conway <[email protected]>
Cc: Davin Shearer <[email protected]>
Cc: PostgreSQL-development <[email protected]>
Subject: Re: Emitting JSON to file using COPY TO
Date: Wed, 06 Dec 2023 11:28:59 -0500
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <CALvfUkBxTYy5uWPFVwpk_7ii2zgT07t3d-yR_cy4sfrrLU=kcg@mail.gmail.com>
	<CALvfUkB2QtG-BXsTwjoLO8ZYUsNFytqjPvZex8stQ0r_qNM7HQ@mail.gmail.com>
	<[email protected]>
	<CALvfUkDxgTppjy-Q_i2znakMFp2vrJdPUEJNyGTL2LcZBOWV6A@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<CALvfUkAbj4Bwg0FjYpvj0-zddcetWg1Sejt=OGBTDskbqOFS_A@mail.gmail.com>
	<[email protected]>
	<CALvfUkD8+bcNs1cYeU3wK9YsyZ7zUjs2aTxO+++Vq7zKeUE7+w@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<! [email protected]>
	<[email protected]>
	<19a5f9d8-bd1f-9! [email protected]>

Andrew Dunstan <[email protected]> writes:
> On 2023-12-06 We 10:44, Tom Lane wrote:
>> In particular, has anyone done any performance testing?
>> I'm concerned about that because composite_to_json() has
>> zero capability to cache any metadata across calls, meaning
>> there is going to be a large amount of duplicated work
>> per row.

> Yeah, that's hard to deal with, too, as it can be called recursively.

Right.  On the plus side, if we did improve this it would presumably
also benefit other callers of composite_to_json[b].

> OTOH I'd rather have a version of this that worked slowly than none at all.

It might be acceptable to plan on improving the performance later,
depending on just how bad it is now.

			regards, tom lane






view thread (37+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Emitting JSON to file using COPY TO
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox