Flink SQL Secrets: Mastering the Art of Changelog Event Out-of-Orderness
出处：
www.ververica.com
作者：
Lincoln Lee, Jun Qin
Alice is a data engineer taking care of real-time data processing in her company. She found that Flink SQL sometimes can produce update (with regard to keys) events. But, with the early versions of Flink, those events can not be written to Kafka directly because Kafka is an append-only messaging system essentially. Fortunately, the Flink community released the connector upsert-kafka in a later version that supports writing update events. Later, she found that the Flink SQL jobs
