public O setParallelism ( int parallelism ) { Preconditions . checkArgument ( parallelism > 0 || parallelism == ExecutionConfig . PARALLELISM_DEFAULT , "The parallelism must be at least one, or ExecutionConfig.PARALLELISM_DEFAULT (use system default)." ) ; this . parallelism = parallelism ; @ SuppressWarnings ( "unchecked" ) O returnType = ( O ) this ; return returnType ; }
Sets the parallelism for this operator . The parallelism must be 1 or more .