Even I'm thinking the same
On Feb 14, 2018 8:34 PM, "David G. Johnston" <david.g.johns...@gmail.com>
> On Wednesday, February 14, 2018, David G. Johnston <
> david.g.johns...@gmail.com> wrote:
>> On Wednesday, February 14, 2018, pavan95 <pavan.postgres...@gmail.com>
>>> Hi all,
>>> Is it possible to upgrade an existing postgresql 9.1 production system to
>>> latest Postgres 10.0 version?
>>> The main requirement is to get rid of downtime. Please help me out!
>> Zero downtime is only possible by standing up a hot-standby then failing
>> over to it. Same-server upgrade you can do via pg_upgrade but it does
>> involve downtime. There are lots of material and options online, including
>> the docs, for setting up hot-standby replication.
> To clarify, you need to use logical replication here since the WAL format
> is not usable across versions.
> pg_upgrade is your simplest option if you can handle its downtime.
> David J.