ksqlDB Stream SQL

ksqlDB is a streaming SQL database built on Apache Kafka that allows SQL queries on event streams. Instead of writing stream processing code in Java, Python, or Scala, you write SQL. You can aggregate, join, transform, and enrich Kafka topics using familiar SQL syntax. ksqlDB runs as a server; users connect via CLI, UI, or API. ksqlDB is maintained by Confluent (the company behind Kafka) and integrates tightly with the Kafka ecosystem. It's used for real-time analytics, data enrichment, stream filtering, and building materialized views from event streams.