We use PostgreSQL and H2 as databases. We find that these databases satisfy the majority of our client's needs. Should you require the use of a commercial database (such as Oracle or SQL Server), we can work with you, but we do not claim to be commercial database experts nor do we have commercial database certifications. We also do not have the resources to install development versions of commercial databases, so we encourage our clients to use open-source databases. We typically will initialize, implement, test, and verify a database model and design, but ongoing database maintenance is the responsibility of the client and/or customer. Typically, we will deliver as low maintenance a database as we can, but if you require us to maintain the database for you, then we will need to negotiate fees above and beyond any contract or agreed-upon terms per project.