Date: Thu, 26 Apr 2018 10:59:10 +0900
From: Michael Paquier <michael@paquier.xyz>
To: Oleg Bartunov <obartunov@postgrespro.ru>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-docs@lists.postgresql.org
Subject: Re: document json[b] limitation
Message-ID: <20180426015910.GC18940@paquier.xyz>
References: 
 <CAF4Au4yV8k53_9YhhNLVhX_xQzmtAjcbvOWN4oFL3Nt2ayDzVA@mail.gmail.com>
 <17093.1524611576@sss.pgh.pa.us>
 <CAF4Au4zf7_39btnAbH1M0sWFc4i0NPPNGfV_EbRbjeCMpj305w@mail.gmail.com>
MIME-Version: 1.0
Content-Type: multipart/signed; micalg=pgp-sha512;
	protocol="application/pgp-signature"; boundary="eqp4TxRxnD4KrmFZ"
Content-Disposition: inline
In-Reply-To: 
 <CAF4Au4zf7_39btnAbH1M0sWFc4i0NPPNGfV_EbRbjeCMpj305w@mail.gmail.com>
Precedence: bulk


--eqp4TxRxnD4KrmFZ
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

On Wed, Apr 25, 2018 at 06:50:51PM +0300, Oleg Bartunov wrote:
> Oops, it should be 256 Mb :)

The numbers you are presenting are right, aka 1GB for json:
=# create table aa (a json);
CREATE TABLE
=# insert into aa select ('{"key":"' || repeat('a', 512 * 1024 * 1024) ||
     repeat('a', 500 * 1024 * 1024) || '"}')::json;
INSERT 0 1
=# insert into aa select ('{"key":"' || repeat('a', 512 * 1024 *
     1024) || repeat('a', 512 * 1024 * 1024) || '"}')::json;
ERROR:  XX000: invalid memory alloc request size 1073741836
LOCATION:  palloc, mcxt.c:934

And 256MB for jsonb:
=# create table ab (a jsonb);
CREATE TABLE
=# insert into aa select ('{"key":"' || repeat('a', 256 * 1024 *
1024) || '"}')::jsonb;
ERROR:  54000: string too long to represent as jsonb string
DETAIL:  Due to an implementation restriction, jsonb strings cannot
exceed 268435455 bytes.

Be sure to use an upper-case "B" to mean bytes and not bits in the
documentation.
--
Michael

--eqp4TxRxnD4KrmFZ
Content-Type: application/pgp-signature; name="signature.asc"

-----BEGIN PGP SIGNATURE-----
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=53G5
-----END PGP SIGNATURE-----

--eqp4TxRxnD4KrmFZ--