예제 #1
0
 public RexNode parameter(ParameterExpression param) {
   int i = parameterList.indexOf(param);
   if (i >= 0) {
     return values.get(i);
   }
   throw new RuntimeException("unknown parameter " + param);
 }
 // override RexShuttle
 public RexNode visitCall(final RexCall call) {
   int i = reducibleExps.indexOf(call);
   if (i == -1) {
     return super.visitCall(call);
   }
   RexNode replacement = reducedValues.get(i);
   if (addCasts.get(i) && (replacement.getType() != call.getType())) {
     // Handle change from nullable to NOT NULL by claiming
     // that the result is still nullable, even though
     // we know it isn't.
     //
     // Also, we cannot reduce CAST('abc' AS VARCHAR(4)) to 'abc'.
     // If we make 'abc' of type VARCHAR(4), we may later encounter
     // the same expression in a ProjectRel's digest where it has
     // type VARCHAR(3), and that's wrong.
     replacement = rexBuilder.makeCast(call.getType(), replacement);
   }
   return replacement;
 }