Re: [PATCH] Support automatic sequence replication

On Mon, Feb 23, 2026 at 11:14 AM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:
>
> Dear Dilip,
>
> > Thanks for clarifying the use case, and I agree this is a valid use
> > case, although I am not completely sure how exactly we are achieving
> > that? I mean sequence sync workers need to fetch the list of all
> > published sequences to identify whether they are in sync with the
> > local sequence state or not?  Or somehow we can avoid that?  If not
> > what we would save, updating the local states of the sequences if they
> > are already in sync?
>
> IIUC, the sequencesync worker first lists all sequences on the subscriber, then
> gets their states on the publisher side. Then the worker updates the state only
> when the sequence between instances is different.
>
> Does it make sense for you?

Thanks, yeah that absolutely makes sense, one of the key requirement
while using the logical replication for the major version upgrade is
how long is the downtime before switchover and thats directly
proportional to the time we take in syncing.  So with automatic
sequence sync if we are ensuring that only the sequences which were
not synced automatically are synced with REFRESH that then this would
be very good feature addition.  However, I will look into the patch to
see how we are taking care of syncing the sequences which are not
already synced.  Have we done any time measurement with very large
number of sequences, that how much time REFRESH SEQUENCES takes with
or without patch?
BEST case(sequences are rarely getting changed), AVERAGE case(only
some sequences are getting frequently modified and others are not) and
WORST case(all sequences are frequently getting modified)

-- 
Regards,
Dilip Kumar
Google