I have recently started an enquiry about which databases jOOQ users are most frequently using. The poll is here:
https://blog.jooq.org/2012/04/12/which-database-are-you-using-jooq-with/

Of course, such a poll is best analysed using jOOQ’s OLAP features. When dumped into a POLL table in our database, we can query the database for the ranking as such:

System.out.println(
create.select(
         denseRank().over().orderBy(POLL.VOTES.desc()),
         POLL.VOTES
             .mul(100)
             .div(sum(POLL.VOTES).over())
             .concat(" %")
             .lpad(4, ' ').as("percent"),
         POLL.DIALECT)
      .from(POLL)
      .orderBy(POLL.VOTES.desc())
      .fetch());

And the winners after 40 votes are:

+----------+-------+-------------------+
|dense_rank|percent|dialect            |
+----------+-------+-------------------+
|         1|22 %   |MySQL              |
|         1|22 %   |Oracle             |
|         2|15 %   |Postgres           |
|         2|15 %   |H2                 |
|         3|10 %   |SQLServer          |
|         4| 7 %   |HSQLDB             |
|         5| 2 %   |Other              |
|         5| 2 %   |DB2                |
|         5| 2 %   |Derby              |
|         6| 0 %   |SQLite             |
|         6| 0 %   |Ingres             |
|         6| 0 %   |Sybase SQL Anywhere|
|         6| 0 %   |Sybase ASE         |
|         6| 0 %   |CUBRID             |
+----------+-------+-------------------+