Horton

Re: [BUG]Update Toast data failure in logical replication

Andres Freund <andres@anarazel.de>

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From: Andres Freund <andres@anarazel.de>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Dilip Kumar <dilipbalaut@gmail.com>, Euler Taveira <euler@eulerto.com>, Michael Paquier <michael@paquier.xyz>, Alvaro Herrera <alvherre@alvh.no-ip.org>, Petr Jelinek <petr.jelinek@enterprisedb.com>, Peter Eisentraut <peter.eisentraut@enterprisedb.com>, Tomas Vondra <tomas.vondra@enterprisedb.com>, Kuntal Ghosh <kuntalghosh.2007@gmail.com>, "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2022-02-07T19:17:58Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. WAL log unchanged toasted replica identity key attributes.

  2. Add new wal_level, logical, sufficient for logical decoding.

  3. Add the notion of REPLICA IDENTITY for a table.

Hi,

On 2022-02-07 08:44:00 +0530, Amit Kapila wrote:
> Right, and it is getting changed. We are just printing the first 200
> characters (by using SQL [1]) from the decoded tuple so what is shown
> in the results is the initial 200 bytes.

Ah, I knew I must have been missing something.


> The complete decoded data after the patch is as follows:

Hm. I think we should change the way the strings are shortened - otherwise we
don't really verify much in that test. Perhaps we could just replace the long
repetitive strings with something shorter in the output?

E.g. using something like regexp_replace(data, '(1234567890|9876543210){200}', '\1{200}','g')
inside the substr().

Wonder if we should deduplicate the number of different toasted strings in the
file to something that'd allow us to have a single "redact_toast" function or
such. There's too many different ones to have a reasonbly simple redaction
function right now. But that's perhaps better done separately. 

Greetings,

Andres Freund