StreamingQueryWrapper — Serializable StreamExecution¶
StreamingQueryWrapper is a serializable interface of a StreamExecution.
StreamingQueryWrapper has the same StreamExecution API and simply passes all the method calls along to the underlying StreamExecution.
StreamingQueryWrapper is created when StreamingQueryManager is requested to create a streaming query (when DataStreamWriter is requested to start an execution of the streaming query).
Demo: Any Streaming Query is StreamingQueryWrapper¶
import org.apache.spark.sql.execution.streaming.StreamingQueryWrapper
val query = spark
.readStream
.format("rate")
.load
.writeStream
.format("memory")
.queryName("rate2memory")
.start
assert(query.isInstanceOf[StreamingQueryWrapper])