code: @Override
  	public Scan open() {
  		// throws an exception if p is not a tableplan.
  		TableScan ts = (TableScan) tp.open();
  		Index idx = ii.open(tx);
  		return new IndexSelectScan(idx, 
  				new SearchRange(ii.fieldNames(), schema(), searchRanges), ts);
  	}
docs: Creates a new index-select scan for this query
  
  @see Plan#open()