[postgis-users] How to migrate to new server when PostGIS generations differ

[Troels Arvin]

I am working on getting rid of an old CentOS 7 server which runs 
Postgres 10+PostGIS 2.4.8, installed from the yum repository at 
https://download.postgresql.org/pub/repos/yum/

The server's databases are to be moved to a new Ubuntu 22 server running 
Postgres 15+PostGIS 3.4, installed from the apt repo at 
http://apt.postgresql.org/pub/repos/apt/

I was hoping I could simply perform a pg_dump on the old server and a 
pg_restore on the new one, but I run into some errors, example:

   pg_restore: error: could not execute query: ERROR:  type 
"public.pgis_abs" does not exist
   Command was: CREATE AGGREGATE public.accum(public.geometry) (
       SFUNC = public.pgis_geometry_accum_transfn,
       STYPE = public.pgis_abs,
       FINALFUNC = public.pgis_geometry_accum_finalfn
   );

Is my pg_dump->pg_restore plan simply not viable? If not, what other 
strategy should I employ?

-- 
Regards,
Troels Arvin