RE: [bug fix] pg_rewind takes long time because it mistakenly copies data files

From: Michael Paquier [mailto:michael(at)paquier(dot)xyz]
> Your patch is able to fix that. I have also checked that after diverging
> the promoted server with more data and inserting data on the old primary
> then the correct set of blocks from the tablespace is fetched as well by
> pg_rewind. This patch also behaves correctly when creating a new relation
> on the promoted server as it copies the whole relation. In short your patch
> looks good to me.

How quick, I was surprised. Thank you so much! I'd be glad if you could be the reviewer in CF:

https://commitfest.postgresql.org/17/1542/

> Creating a test case for this patch would be nice, however this needs a
> bit of work so as the tablespace map can be used with pg_basebackup and
> PostgresNode.pm (or use raw pg_basebackup commands in pg_rewind tests):
> - PostgresNode::init_from_backup needs to be able to understand extra
> options given by caller for pg_basebackup.
> - RewindTest::create_standby should be extended with extra arguments given
> for previous extension.
> :(

That sounds difficult from your way of saying... but this may be a good opportunity to look into the TAP tests.

Regards
Takayuki Tsunakawa