CUBRID is an open source database management system highly optimized for web applications. CUBRID assures the high performance, stability, scalability, and high availability which are required for mission-critical Internet applications.
With cubrids you can use multiple different databases in one application (mysql as well). It's very powerful but also really complex to get up & running with! We solved our integration problems using this platform by connecting MySQL / Oracle DBs together via ODBC drivers like OraDS/Oracle8iClientDriver/. You simply have more flexibility than other solutions when it comes down solving issues that arise from having such heterogeneous datamodel structures working handinhand within your singleโฆ
Pros
Multiple database connections
High performance even though everything is done through memory.