Nothing seems to change in the top-5 .… Boring?
We would have thought that the IoT is generating high volumes of data and that IoT and DataScience are driving the use of all sorts of “big data” systems. Trend-wise, this is not “visible” in the db-engines measurements, yet.
We like to add our own conclusions to this: RDBMS still rules the DB world.
From our own experience, we observe that even the users of big-data, the key-value stores, the schema-on-read-users and the systems with object-stores or document-stores all come back to processing (and presenting) data in tabular, in “relational” form.
And that SQL is the preferred and most-used way to handle and process data.
Add to that the fact that the large players are promoting and improving their capabilities to handle multi-model data such as Graph-data and Object-stores, which brings these data-sets in the otherwise “known” area of the RDBMS. The “need” for using more exotic, non-RDBMS systems seems to diminish.
Hence RDBMS still rules the data-world.
And looking at the graphs at db-engine: this may remain the case for the foreseeable future.