How do I solve a "server version mismatch" with pg_dump when I need BOTH PostgreSQL servers installed?
I installed two PostgreSQL servers in my computer. One is 9.1 and the other is 9.3. I need both servers installed.
When I run pg_dump, however, I get a version mismatch error:
server version: 9.3.6; pg_dump version: 9.1.15
pg_dump: aborting because of server version mismatch
How can I solve it? (Cannot uninstall either version - I installed the 9.1 first and the 9.3 many months later - I need both database servers installed).
TL;DR: if both PostgreSQL instances are managed by the Ubuntu packages (as they should), just use the --cluster
option to select the PostgreSQL instance to backup, and it will automatically choose the corresponding version of pg_dump:
pg_dump --cluster 9.1/main [other pg_dump options]
or
pg_dump --cluster 9.3/main [other pg_dump options]
.
main
is just a default value, run pg_lsclusters
to see your actual names in the Cluster
column.
How it works: as installed by the Ubuntu packages, /usr/bin/pg_dump
is actually a soft-link to /usr/share/postgresql-common/pg_wrapper
, whose purpose is precisely to select the correct instance and run the corresponding binary. --cluster
does not exist in the stock PostgreSQL commands, it's a Debian/Ubuntu addition that is meant to address this multiple versions/multiple paths problem.
This is the same for psql
, createdb
, createuser
, etc. about 18 postgres commands in /usr/bin
are actually managed by pg_wrapper
.
See man pg_wrapper for more.
You can use:
sudo find / -name pg_dump
to find your versions of pg_dump
in my case: /usr/pgsql-9.6/bin/pg_dump
so next we can do:
sudo ln -sfn /usr/pgsql-9.6/bin/pg_dump /usr/bin/pg_dump
in order to update to the one we need