How to downgrade/have a previous version of Postgres DB in Postgres.app

Question

I have installed Postgres.app from here (http://postgresapp.com) a couple of days ago. It comes with Postgres 9.4.4.

Today I realised that the software I am using officially supports only Postgres 9.3. The 9.4.4 version works, but sometimes there are DB locks.

Is there a way to downgrade my current db (very small in size, created just for testing), which is version 9.4.4 to 9.3? Or is it possible to create another DB with version 9.3 without uninstalling current version of Postgres.app?

OS: OS X Yosemite 10.10.4

Thank you.

Answer 1

1. install postgres 9.3 server and client to your mac
2. run locate initdb expected in /Library/PostgreSQL/9.3/bin/initdb let's assume it is there
3. create 9.3 instance /Library/PostgreSQL/9.3/bin/initdb -D /new_data_directory
4. export 9.4 db /Library/PostgreSQL/9.3/bin/pg_dump -U 94_username -d 94_database >somefile.dmp
5. shutdown old /Library/PostgreSQL/9.4/bin/pg_ctl stop -m fast
6. startup new /Library/PostgreSQL/9.3/bin/pg_ctl start 7.create 93 db /Library/PostgreSQL/9.3/bin/psql -U 93_superuser_user -c "create database IMPORT_DB"
7. import 93 db /Library/PostgreSQL/9.3/bin/psql -U 93_superuser_user -f somefile.dmp IMPORT_DB

I don't know if there are articles on this topic. I know I sound old fashion, but maybe manuals? :) and experience