Unlike Confluent’s Kafka-based platform, KarelDB is not a streaming database. Yokota nevertheless flagged the relational database largely because it’s based on open-source components backed by Kafka. Hence, he reckons there’s a chance it could take off.
Those open source components include Calcite, an SQL framework that pushes relational queries to the data store, an approach seen as providing more efficient processing. Yokota noted that KarelDB would “automatically benefit” from upcoming Calcite optimizations.
Other open source projects such as the Apache Flink stream processing engine also have leveraged Calcite, including an SQL API. Calcite also includes an SQL parser.
Kafka already had KSQL for Kafka Streams, but this is a totally different validation of Feasel’s Law.