使用与 Kafka 主题消息键相同的 ROWKEY 创建 KSQL 表

Question

I'm creating a KTable from a topic with JSON value format, the producers of the topic also include a key for each message at Kafka level and JSON message itself contains a JSON property called key which I use as ROWKEY in the following statement:

create table SUBSCRIPTIONS(key varchar, application_id varchar, subscription_id varchar) with (KAFKA_TOPIC='INCOMING_SUBSCRIPTIONS', VALUE_FORMAT='JSON', KEY='key');

Is there a way to create a KSQL table using the key from the messages in the the topic as ROWKEY so I don't have to duplicate the key value at topic level?

Answer 1

No, this is not currently possible in KSQL. The key needs to be present in the message value as well as the key itself.

There is work underway for KSQL 5.2 that will improve how keys are handled, so stay tuned…