public O setParallelism ( int dop ) { if ( dop < 1 ) { throw new IllegalArgumentException ( "The parallelism of an operator must be at least 1." ) ; } this . dop = dop ; @ SuppressWarnings ( "unchecked" ) O returnType = ( O ) this ; return returnType ; }
Sets the degree of parallelism for this operator . The degree must be 1 or more .