Joining Highly Skewed Streams in Flink SQL
Source :
www.ververica.com
Author :
Karl Fried
Flink SQL is a powerful tool which unifies batch and stream processing. It provides low-code data analytics while complying with the SQL standard. In production systems, our customers found that as the workload scales, the SQL jobs that used to work well may slow down significantly, or even fail. And data skews is a common and important reason. Data skew refers to the asymmetry of the probability distribution of a variable about its mean. In other words