v.20.3Improvement

Possibility to Add Key & Timestamp When Inserting Data to Kafka

Possibility to add key & timestamp for the message when inserting data to Kafka. Fixes #7198 #8969 (filimonov)
Added support for specifying the message key and timestamp when inserting data into Kafka tables in ClickHouse.

Why it matters

This feature addresses the need to set a Kafka message key and a custom timestamp during data insertion, enhancing integration flexibility and allowing better control over Kafka message metadata.

How to use it

When inserting data into a Kafka table, users can specify the message key and timestamp fields to be sent with each Kafka message. This is done by including the key and timestamp columns in the insert statement or table definition, enabling precise control over the Kafka message metadata.