DB-Engines Ranking
http://db-engines.com/en/ranking
The DB-Engines Ranking ranks database management systems according to their popularity. The ranking is updated monthly.
Read more about the method of calculating the scores.
http://db-engines.com/en/ranking_trend
Redis
MongoDB
MySQL
# 2018
http://www.cnblogs.com/xgqfrms/p/5866447.html
https://db-engines.com/en/ranking
https://db-engines.com/en/ranking_trend
# 2020
1