Re: [PATCH] pg_upgrade: add --initdb option to create the new cluster automatically

> On 14 Jul 2026, at 16:42, Bohyun Lee <bohyun(dot)lee(at)databricks(dot)com> wrote:

Thanks for the update.

Right now most of the focus is on getting v19 ready to ship, I recommend
registering the patch in the commitfest app to make sure it's not lost (if you
already did I just failed to find it).

> On external wrapper vs. in-tree: the point of --initdb is deriving the new cluster's settings (WAL segment size, checksums, encoding, locale) from the old cluster, exactly what people get wrong by hand and only discover when check_control_data() fails. pg_upgrade already reads the old control data, so doing it here reuses that rather than making a wrapper rediscover it. I'm open to being convinced otherwise.

Maybe. Since it won't be a mandatory step, we still need to document the
process properly and I see that as the first step. Currently the docs have
"use compatible initdb flags that match the old cluster" which clearly isn't
particularly helpful.

--
Daniel Gustafsson