You can see that with so called "Big Data" tools. Those which originated as databases (Mongo), ended up adding "Map-reduce" feature. Those which started as map-

You can see that with so called "Big Data" tools. Those which originated as databases (Mongo), ended up adding "Map-reduce" feature. Those which started as map-reduce tools evolved to support SQL (Hadoop->Spark). Those which started as SQL engines (Spark) added support for streaming, while those who started as steaming platforms (Kafka) added SQL support (KSQLDB). Traditional DB engines evolve to allow document data (Postgres with JSON column type). One more decade until one-tool-to-rule-them-all emerges :)