On 12/6/19 8:14 AM, Julie Nishimura wrote:
Thank you everybody for your suggestions.
So, to summarize - we can run pg_upgrade from 8.3 to 9.4 (in place), fix
app related issues (if any), then migrate to a version more recent than
9.6, either through pg_basebackup or through logical replication (if we
would upgrade to version 10).
First step requires downtime. Second does not. Correct?
Well pg_basebackup is a binary copy so I am pretty sure you cannot use
the copy from an old Postgres version with a new Postgres major version.
I am also pretty sure whatever you do there is going to be some
downtime. Left unsaid to date and relevant to downtime:
1) Space/machines available to juggle multiple Postgres instances?
2) Network proximity of above.
3) Whether it is essential all the databases remain in a single cluster?
-Julie
------------------------------------------------------------------------
*From:* Tom Lane <t...@sss.pgh.pa.us>
*Sent:* Wednesday, December 4, 2019 5:28 AM
*To:* Stephen Frost <sfr...@snowman.net>
*Cc:* Laurenz Albe <laurenz.a...@cybertec.at>; Michael Paquier
<mich...@paquier.xyz>; Julie Nishimura <juliez...@hotmail.com>;
pgsql-general@lists.postgresql.org <pgsql-general@lists.postgresql.org>;
pgsql-general <pgsql-gene...@postgresql.org>
*Subject:* Re: upgrade and migrate
Stephen Frost <sfr...@snowman.net> writes:
* Laurenz Albe (laurenz.a...@cybertec.at) wrote:
Right, Slony is the way to go, since pg_upgrade doesn't support 8.3.
I would upgrade to a version more recent than 9.6.
So... there's a bit of history here. pg_upgrade in 9.4 actually does
support upgrading from 8.3.X. Support for upgrading from 8.3 was
removed in 2209b3923a7afe0b6033ecfea972219df252ca8e.
Yeah. Also note that 8.3 to 9.6-or-newer is going to be a pretty
huge jump in terms of minor compatibility issues (have you read
all the relevant release notes?). So there's something to be said
for breaking this down into two steps: update to 9.4, test/fix
your applications against that, then make a second jump to something
current. Each of those jumps could be handled by the respective
version of pg_upgrade. I concur with Laurenz's advice that stopping
at 9.6 is probably not your best choice for a migration today.
regards, tom lane
--
Adrian Klaver
adrian.kla...@aklaver.com
