Date: Fri, 22 Nov 2019 17:12:48 +0100
From: Tomas Vondra <tomas.vondra@2ndquadrant.com>
To: =?utf-8?Q?Ond=C5=99ej?= Jirman <ienieghapheoghaiwida@xff.cz>
Cc: Tom Lane <tgl@sss.pgh.pa.us>, pgsql-bugs@lists.postgresql.org
Subject: Re: BUG #16129: Segfault in tts_virtual_materialize in logical
 replication worker
Message-ID: <20191122161248.qnzeoh6t7fvg5wl3@development>
References: <20191121155707.pqkgjphh65o5fapz@core.my.home>
 <20191121161502.xfiy65i3cm6adscr@core.my.home>
 <20191121165752.dffge6bh756xlfdg@development>
 <20191121173555.midj6vp4dmiiqs24@core.my.home>
 <20191121185844.6qsqhwzzuhu3fpsg@core.my.home>
 <20191121214115.3tgefmvkmrzaim74@development>
 <20191121220854.ebdzjtloel56sfwu@development>
 <20191122003626.ydgwvjfx363blgip@core.my.home>
 <16189.1574383534@sss.pgh.pa.us>
 <20191122005401.bkdpmtqwuu6mvnyg@core.my.home>
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In-Reply-To: <20191122005401.bkdpmtqwuu6mvnyg@core.my.home>
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On Fri, Nov 22, 2019 at 01:54:01AM +0100, Ondřej Jirman wrote:
>On Thu, Nov 21, 2019 at 07:45:34PM -0500, Tom Lane wrote:
>> =?utf-8?Q?Ond=C5=99ej?= Jirman <ienieghapheoghaiwida@xff.cz> writes:
>> > On Thu, Nov 21, 2019 at 11:08:54PM +0100, Tomas Vondra wrote:
>> >> 1) Print newtup.values and newtup.changed matches, so that we can check
>> >> it contains the tuple I shared before? There should be 8 elements in
>> >> each, with 'values' being values formatted as text, and 'changed' being
>> >> flags which values were updated.
>>
>> > newtup.changed
>>
>> > {true, true, false, true, true, true, true, true, false <repeats 1656 times>}
>>
>> So column 3 is not getting replaced.  That seems to jibe with my
>> theory that slot_modify_cstrings is failing to handle that case
>> correctly.  Can you try applying the patch I posted and see if
>> it fixes the issue for you?
>
>With the patch the replication resumes, without a crash.
>
>confirmed_flush_lsn is now same for all my replication slots.
>
>thank you and regards,

Can you show us the attribute list as defined in the system, including
e.g. dropped columns? That is, something like

   SELECT attnum, attname, atttypid FROM pg_attribute
    WHERE attrelid = 'public.videos'::regclass;

both from the published and subscriber.

regards

-- 
Tomas Vondra                  http://www.2ndQuadrant.com
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services