Scuba is a distributed in-memory database built at Facebook. It is, in essence, a time-series data analysis database aimed towards serving real-time analytical queries approximately. Scuba aims to keep data ingestion latency low and handles huge data inflow by expelling old data from the memory.
Scuba supports a web-based interface, a SQL interface through the command line, and a custom Thrift-based API for running queries from application code. All the queries originating from the SQL interface and the web interface ultimately rely on the Thrift interface to query the database backend.
N-ary Storage Model (Row/Record)
As their primary workload is analytical, Scuba in future is considering shifting to the columnar layout.
https://research.fb.com/publications/scuba-diving-into-data-at-facebook/
2013