When I try to migrate a database from Postgres 9.0 to a new server using Postgres 10.8, I got the error from pg_restore which says
pg_restore: [archiver (db)] could not execute query: ERROR: constraint "idpost" for relation "classification" already exists
After looking into the dataset, I found two constraints of the same name
idpost was created. However, I am not sure whether this is because the version 9.0 allows constraints of the same name while version 10.8 forbids it. Is there any way I can confirm my guess?