StreamingQuery provides an interface for interacting with a query that executes continually in background.
|
Note
|
StreamingQuery is called continuous query or stream query.
|
A StreamingQuery has a name. It belongs to a single SQLContext.
|
Note
|
StreamingQuery is a Scala trait with the only implementation being StreamExecution
|
It can be in two states: active (started) or inactive (stopped). If inactive, it may have transitioned into the state due to an StreamingQueryException (that is available under exception).
It tracks current state of all the sources, i.e. SourceStatus, as sourceStatuses.
There could only be a single Sink for a StreamingQuery with many `Source’s.
StreamingQuery can be stopped by stop or an exception.