We are doing a full migration/new installation from a very old version of software. The current installations use the evaluation copies of the databases, but this is not ideal and in some cases, no longer supported. We are looking at using either PostgreSQL or MySQL on a Windows platform. Is it possible to have only one database engine/instance handle the all 4 of the applications (Jira, Confluence, Bitbucket, and Bamboo), or do you need 4 different database instances, or some mix? We are finalizing the sizings of our VMs for installation, and I need to understand the database situation to finalize the sizing.