On 11/18/20 8:05 AM, Stephen Haddock wrote:
Hello,
When upgrading an older version of postgres, version 8.4 for example, to
a newer version such as 9.6, does the data have to be migrated immediately?
It looks like the recommended method is to dump the data, upgrade,
initialize a new cluster, and then restore the dumped data into the
newer version. My question is whether the data dump and restore must be
done immediately. It appears that 9.6 is able to run against the older
cluster (DB service starts, queries work, etc), and the data could be
migrated days or weeks later. I don't know if that is asking for issues
down the line though such as 9.6 corrupting the data due to
incompatibilities between the two versions.
https://www.postgresql.org/docs/9.6/app-pgdump.html
"Because pg_dump is used to transfer data to newer versions of
PostgreSQL, the output of pg_dump can be expected to load into
PostgreSQL server versions newer than pg_dump's version. pg_dump can
also dump from PostgreSQL servers older than its own version.
(Currently, servers back to version 7.0 are supported.) "
The above is for Postgres 9.6 version of pg_dump. Newer versions(10+) go
back to Postgres 8.0. You can dump the old server at anytime. The
important thing to remember is to dump the old server using the new
servers version of pg_dump. So in your case pg_dump(9.6) against
server(8.4).
Thanks!
--
Adrian Klaver
adrian.klaver@xxxxxxxxxxx
