olemus
andmebaasihalduri komponent, mille ülesandeks on andmete tegelik salvestus, võtt, uuendus ja kustutus; enamasti on võimalik eraldi kasutada andmebaasihalduri rakendusliidese kaudu
Wiktionary:
the underlying component that a database management system uses to create, retrieve, update and delete data

ülevaateid
https://www.techopedia.com/definition/1188/database-engine
https://image.slidesharecdn.com/databaseengine-13316327496315-phpapp02-120313050124-phpapp02/95/database-engine-2-1024.jpg
https://en.wikipedia.org/wiki/Database_engine
https://hackernoon.com/how-sql-database-engine-work-483e32o7
https://medium.com/@grepdennis/how-a-sql-database-engine-works-c67364e5cdfd

näiteid
https://www.kdnuggets.com/2016/06/top-nosql-database-engines.html
https://dc.etsu.edu/cgi/viewcontent.cgi?article=2271&context=etd