Access Layer
Apache Hive
Apache Kudu
Document
AWS Dynamo
CouchDB
Couchbase
MongoDB
PouchDB
dynomite
Key-Value
Memcached
Riak
etcd
redis
Relational
AWS Redshift
CockroachDB
Search Engine
Elasticsearch
Splunk
Time Series
Druid
Web Service
AWS S3
Wide Column
Cassandra
HBase

see Database ranking:

  1. Oracle
  2. MySQL
  3. MS SQL Server
  4. MongoDB
  5. PostgreSQL
  6. DB2
  7. Cassandra
  8. MS Access
  9. redis
  10. SQLite