postgresql downgrade issue

Q:

Dear Support Team, 

If we use ubuntu server to install postgresql9.4, how can we keep original data to downgrade postgresql from 9.4 to 9.3. Would it be possible to support the guidance for us ? Thank you.
Best Regards, Anderson Hsu
 
A:
Actually, he should use plain text format (pg_dump default) because PostgreSQL doesn't support downgrade. 
 
 
 
 
 
参考:
http://postgresql.nabble.com/postgresql-downgrade-issue-td5873698.html