Most popular relational databases used from within Java Virtual Machines– 2016 edition
Here is the article that exposes the data extracted from the applications monitored by Plumbr monitoring solution. The data below originates from 618 different companies and 3,172 unique Java Virtual Machines
As someone commented on reddit :
“Unfortunately it seems to include testing code in it’s analysis. I doubt HyperSQL and H2 are used that extensively in production but H2 is more or less the de facto integration test DB in Java land since it can mimic other dialects so well.”