Date: Wed, 1 Jan 2020 20:09:18 +0100
From: David Fetter <david@fetter.org>
To: Robert Haas <robertmhaas@gmail.com>
Cc: David Steele <david@pgmasters.net>,
	Tels <nospam-pg-abuse@bloodgate.com>,
	Suraj Kharage <suraj.kharage@enterprisedb.com>,
	Rushabh Lathia <rushabh.lathia@gmail.com>,
	Andrew Dunstan <andrew.dunstan@2ndquadrant.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>,
	Jeevan Chalke <jeevan.chalke@enterprisedb.com>,
	vignesh C <vignesh21@gmail.com>
Subject: Re: backup manifests
Message-ID: <20200101190917.GR32763@fetter.org>
References: 
 <CAF1DzPXcCgXP2awVaH4uHovPo77JdLYPAYShzwnSPMVzdUmxSQ@mail.gmail.com>
 <CA+TgmoZdJ=vBoDU1Skv52Prybp36kMvmpTDBXbmoky0owNgMiA@mail.gmail.com>
 <CAF1DzPW1CAjR7FG86b-OL+hAP2xGqmBUtv0WtRhDz+r+Mwy-Hw@mail.gmail.com>
 <CA+TgmoYY5LXfbmeCO3gpCoCJcqNj0125PO7B7ecuJjnoEdB08A@mail.gmail.com>
 <CAF1DzPXOofDsdSqgEtzpegfcvqB_1TND_h_8uQrvJuVvx-4pDA@mail.gmail.com>
 <CA+TgmobnSHW3upkS_x6D=cM9A3jT9ZA0pcH0FJitBfkyW7sFJA@mail.gmail.com>
 <f97892ef565db763c97f23566c2cb6e5@bloodgate.com>
 <20191231174325.GQ32763@fetter.org>
 <7cb79c9e-8377-b2b5-3fa4-9775e1aca1fe@pgmasters.net>
 <CA+Tgmoa+oTgwobVQFb+BGSaGLxS7_tqZJbgUP=waskfb83wvKQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: 
 <CA+Tgmoa+oTgwobVQFb+BGSaGLxS7_tqZJbgUP=waskfb83wvKQ@mail.gmail.com>
User-Agent: Mutt/1.9.4 (2018-02-28)
Precedence: bulk

On Wed, Jan 01, 2020 at 01:43:40PM -0500, Robert Haas wrote:
> On Tue, Dec 31, 2019 at 9:16 PM David Steele <david@pgmasters.net> wrote:
> > > That said, I agree that there's no reason to come up with a bespoke
> > > format and parser when JSON is already available in every PostgreSQL
> > > installation.  Imposing a structure atop that includes a version
> > > number, as you suggest, seems pretty straightforward, and should be
> > > done.
> >
> > +1.  I continue to support a format that would be easily readable
> > without writing a lot of code.
> 
> So, if someone can suggest to me how I could read JSON from a tool in
> src/bin without writing a lot of code, I'm all ears. So far that's
> been asserted but not been demonstrated to be possible. Getting the
> JSON parser that we have in the backend to work from frontend doesn't
> look all that straightforward, for reasons that I talked about in
> http://postgr.es/m/CA+TgmobZrNYR-ATtfZiZ_k-W7tSPgvmYZmyiqumQig4R4fkzHw@mail.gmail.com

Maybe I'm missing something obvious, but wouldn't combining
pg_read_file() with a cast to JSONB fix this, as below?

shackle@[local]:5413/postgres(13devel)(892328) # SELECT jsonb_pretty(j::jsonb) FROM pg_read_file('/home/shackle/advanced_comparison.json') AS t(j);
            jsonb_pretty            
════════════════════════════════════
 [                                 ↵
     {                             ↵
         "message": "hello world!",↵
         "severity": "[DEBUG]"     ↵
     },                            ↵
     {                             ↵
         "message": "boz",         ↵
         "severity": "[INFO]"      ↵
     },                            ↵
     {                             ↵
         "message": "foo",         ↵
         "severity": "[DEBUG]"     ↵
     },                            ↵
     {                             ↵
         "message": "null",        ↵
         "severity": "null"        ↵
     }                             ↵
 ]
(1 row)

Time: 3.050 ms

> As to the suggestion that a version number be included, that's been
> there in every version of the patch I've posted.

and thanks for that!

Best,
David.
-- 
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

Remember to vote!
Consider donating to Postgres: http://www.postgresql.org/about/donate