Hi, Welcome to the Flink community!
A DataStreamSource is a DataStream. It is normally used as the starting point of a DataStream. All related methods in StreamExecutionEnvironment that create a DataStream return actually a DataStreamSource, because it is where a DataStream starts. Commonly, you don't care about DataStreamSource, just use DataStream even if methods in StreamExecutionEnvironment return a DataStreamSource [1]. DataStreamSource created by those methods in StreamExecutionEnvironment will use built-in SourceTranfromation. If you want to modify the configuration of the transformation, you can specifically use the DataStreamSource type(instead of DataStream) which provides some setter methods extended from SingleOutputStreamOperator. Best regards, Jing [1] https://nightlies.apache.org/flink/flink-docs-master/docs/dev/datastream/overview/ On Wed, Sep 14, 2022 at 3:23 PM Noel OConnor <noel.ocon...@gmail.com> wrote: > Hi, > I'm new to flink and I'm trying to integrate it with apache pulsar. > I've gone through the demos and I get how they work but one aspect > that I can't figure out is what's the difference between a DataStream > and a DataStreamSource. > When would you use one over the other? > > cheers > Noel >
