Streaming databases are essential for building real-time Generative AI (GenAI) applications due to their ability to process continuous data streams in real time, enabling immediate actions and insights within applications and systems. They support a wide range of real-time applications across all industries by collecting, processing, and analyzing data as soon as it's available. Key benefits for GenAI applications include real-time data processing, scalability and performance, and easy integration with AI tools. Top streaming databases include open-source options like Apache Kafka, RisingWave, and Arroyo; source-available platforms such as KsqlDB, Materialize, and EventStoreDB; and closed-source solutions like Timeplus and DeltaStream. When selecting a streaming database for GenAI applications, consider performance metrics, scalability, ease of use and integration, and cost considerations.