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

tanghy <tanghy.fnst@fujitsu.com>

From: "tanghy.fnst@fujitsu.com" <tanghy.fnst@fujitsu.com>

To: Dilip Kumar <dilipbalaut@gmail.com>

Cc: pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2021-05-31T02:34:21Z

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 →

WAL log unchanged toasted replica identity key attributes.
- 5e01001ffb38 15.0 landed
- b5e060473273 10.21 landed
- 1cd5802ac69a 11.16 landed
- ce349cf176e2 12.11 landed
- caa231be97df 13.7 landed
- 04645bbcae72 14.3 landed
Add new wal_level, logical, sufficient for logical decoding.
- e55704d8b2fe 9.4.0 cited
Add the notion of REPLICA IDENTITY for a table.
- 07cacba983ef 9.4.0 cited

On Friday, May 28, 2021 6:51 PM, Dilip Kumar <dilipbalaut@gmail.com> wrote:
> Seems you did not set the replica identity for updating the tuple.
> Try this before updating, and it should work.

Thanks for your reply. I tried it.

> ALTER TABLE toasted_key REPLICA IDENTITY USING INDEX toasted_key_pkey;

This didn't work.

> or
> 
> ALTER TABLE toasted_key REPLICA IDENTITY FULL.

It worked.

And I noticed if the length of PRIMARY KEY (toasted_key) is short, data could be synchronized successfully with default replica identity. 
Could you tell me why we need to set replica identity?

Regards
Tang