Relaxed Contiguity suport in cep sql

[张万新]

Hi all,

I noticed that in flink 1.9.0 cep sql with blink planner, using "(A -> B)"
to define a pattern A followed by pattern B is not supported, but it's
supported in blink branch.

I'd like to know why this feature is removed in 1.9.0 blink planner, and is
there any plan to support it in the next release?

regards.