H2 is a leading relational database management system written in Java. H2 can run in client-side server mode and can  be embedded in Java applications. H2, the Java SQL database is open source and fast. The Java Database Connectivity API provides universal data access with Java.  H2 supports a subset of the SQL standard and the disk footprint is about 1.5 MB.
DataVirtuality Benefits
Connect in 5 minutes
DataVirtuality is providing a simple wizard to type in your data source credentials to establish a connection. It only takes minutes and you see your data in a SQL query-able tables instantly after.
SQL Transformation
Query connected data sources with SQL. Query, join and integrate data from Google Analytics, Salesforce, Oracle, MySQL and many more data sources using SQL commands.
Read and write data
Read and write data from connected data sources. Integrate data into an analytical database and write data back to data sources based on triggers.