[KAFKA-17893] Support record keys in the foreignKeyExtractor argument of KTable foreign join

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 4.0.0
• Component/s: streams
• Labels: KIP
• Assignee: Peter Lee
• Reporter: Piotr Jaszkowski
• Created: 29/Oct/24 15:31
• Updated: 03/Dec/24 18:06
• Resolved: 03/Dec/24 18:06

Description

Only accepting record values in the foreignKeyExtractor  is an unnecessary limitation that forces weird topologies.

See discussion in https://forum.confluent.io/t/why-foreignkeyextractor-does-not-accept-key/12427/2.

KIP-1104: https://cwiki.apache.org/confluence/display/KAFKA/KIP-1104%3A+Allow+Foreign+Key+Extraction+from+Both+Key+and+Value+in+KTable+Joins 

Issue Links

• links to: GitHub Pull Request #17756