I think it's correct that (2) directly influences (1). And I think that most corporate groups are willing to hire an Oracle/MS SQL DBA with small amounts of ex

I think it's correct that (2) directly influences (1). And I think that most corporate groups are willing to hire an Oracle/MS SQL DBA with small amounts of experience but the carrying the right certifications. To expand a bit, IMO - that scenario doesn't really exist for PostgreSQL DBAs, you are either experienced or inexperienced (with no weight-carrying certificate to complement credentials). Hence the corporate environment won't hire an entry-level DBA who has no certs to validate the hire, and they won't justify the seemingly added cost of an experienced PostgreSQL DBA.