Question

I recently installed the heroku dev database. Then when I type into the command line heroku pg:info I get THREE databases.

=== SHARED_DATABASE (DATABASE_URL)
Data Size    808k

=== HEROKU_POSTGRESQL_BRONZE
Plan         Dev
Status       available
Connections  1
PG Version   9.1.3
Created      2012-05-14 17:47 UTC
Tables       0
Conn Info    "host=XXXXXX.compute-1.amazonaws.com
             port=5432 dbname=resourceXXXXX
             user=abcXXXXX sslmode=require
             password=XXXXXXXXX"

=== HEROKU_POSTGRESQL_CHARCOAL
Plan         Dev
Status       available
Connections  1
PG Version   9.1.3
Created      2012-05-13 19:08 UTC
Tables       0
Conn Info    "host=XXXXXXX.compute-1.amazonaws.com
             port=5432 dbname=resourceXXXXX
             user=YYYYYY sslmode=require
             password=XXXXXXXXXXXXXXXX"

=== HEROKU_POSTGRESQL_GREEN
Plan         Dev
Status       available
Connections  1
PG Version   9.1.3
Created      2012-05-13 19:06 UTC
Tables       0
Conn Info    "host=XXXXXXXXXXXX.compute-1.amazonaws.com
             port=5432 dbname=resourceXXXXXX
             user=XXXXXXXXXX sslmode=require
             password=XXXXXXXXXXXXXX"

The host, resource, user, and password are different for each.

Why are there three? What’s the difference between them?

Answer 1

With the dev plan similar to the production plan you are able to add multiple databases. Each of these is a unique database and you can connect to each of them individually.

If you wished to remove a database if you did not intend to add three you could:

heroku addons:remove HEROKU_POSTGRESQL_GREEN

To promote one of those to your primary database you may:

heroku pg:promote HEROKU_POSTGRESQL_GREEN

You may also connect to each of them individually:

heroku pg:psql HEROKU_POSTGRESQL_RED