public inbox for [email protected]
help / color / mirror / Atom feedFrom: Tom Lane <[email protected]>
To: Peter Geoghegan <[email protected]>
Cc: [email protected]
Subject: default opclass for jsonb (was Re: Call for GIST/GIN/SP-GIST opclass documentation)
Date: Tue, 08 Apr 2014 17:46:22 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAM3SWZRAxisGCdODhbgeiNL6tayqL18XMzun4W3xesASmKfwDA@mail.gmail.com>
References: <[email protected]>
<CAM3SWZQGZyqSBzaFZ4gmtnQZpcXLE=ceUL_O29gtMgnP=AvC+g@mail.gmail.com>
<[email protected]>
<CAM3SWZRAxisGCdODhbgeiNL6tayqL18XMzun4W3xesASmKfwDA@mail.gmail.com>
List-Unsubscribe: <mailto:[email protected]?body=unsub%20pgsql-hackers>
Peter Geoghegan <[email protected]> writes:
> On Tue, Apr 8, 2014 at 2:34 PM, Tom Lane <[email protected]> wrote:
>> (BTW, wasn't there some discussion of changing our minds about which
>> one is the default? We already have one bug report complaining about
>> jsonb_ops' size restriction, so that seems to be evidence in favor
>> of changing ...)
> Yes, there was. I very nearly came down on the side of making
> jsonb_hash_ops the default, but given that it doesn't make all
> operators indexable, I ultimately decided against supporting that
> course of action. I thought that that would be an odd limitation for
> the default GIN opclass to have. It was a very close call in my mind,
> and if you favor changing the default now, in light of the few
> complaints we've heard, I think that's a reasonable decision. That
> said, as I noted in the main -bugs thread, the case presented is
> fairly atypical.
Well, let me see if I understand the situation correctly:
* jsonb_ops supports more operators
* jsonb_hash_ops produces smaller, better-performing indexes
* jsonb_ops falls over on inputs with wide field values, but
jsonb_hash_ops does not
If that's an accurate summary then I would say that we've got
the default backwards. I would much rather tell people "you
can have more operators supported, but here are the tradeoffs"
than have a default that fails under evidently-not-so-improbable
cases.
regards, tom lane
--
Sent via pgsql-hackers mailing list ([email protected])
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers
view thread (65+ 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]
Subject: Re: default opclass for jsonb (was Re: Call for GIST/GIN/SP-GIST opclass documentation)
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