public void onMatch(RelOptRuleCall call) {
          CalcRel calc = (CalcRel) call.getRels()[0];
          RexProgram program = calc.getProgram();
          final List<RexNode> exprList = program.getExprList();

          // Form a list of expressions with sub-expressions fully
          // expanded.
          final List<RexNode> expandedExprList = new ArrayList<RexNode>(exprList.size());
          final RexShuttle shuttle =
              new RexShuttle() {
                public RexNode visitLocalRef(RexLocalRef localRef) {
                  return expandedExprList.get(localRef.getIndex());
                }
              };
          for (RexNode expr : exprList) {
            expandedExprList.add(expr.accept(shuttle));
          }
          if (reduceExpressions(calc, expandedExprList)) {
            final RexProgramBuilder builder =
                new RexProgramBuilder(
                    calc.getChild().getRowType(), calc.getCluster().getRexBuilder());
            List<RexLocalRef> list = new ArrayList<RexLocalRef>();
            for (RexNode expr : expandedExprList) {
              list.add(builder.registerInput(expr));
            }
            if (program.getCondition() != null) {
              final int conditionIndex = program.getCondition().getIndex();
              final RexNode newConditionExp = expandedExprList.get(conditionIndex);
              if (newConditionExp.isAlwaysTrue()) {
                // condition is always TRUE - drop it
              } else if ((newConditionExp instanceof RexLiteral)
                  || RexUtil.isNullLiteral(newConditionExp, true)) {
                // condition is always NULL or FALSE - replace calc
                // with empty
                call.transformTo(new EmptyRel(calc.getCluster(), calc.getRowType()));
                return;
              } else {
                builder.addCondition(list.get(conditionIndex));
              }
            }
            int k = 0;
            for (RexLocalRef projectExpr : program.getProjectList()) {
              final int index = projectExpr.getIndex();
              builder.addProject(
                  list.get(index).getIndex(),
                  program.getOutputRowType().getFieldList().get(k++).getName());
            }
            call.transformTo(
                new CalcRel(
                    calc.getCluster(),
                    calc.getTraits(),
                    calc.getChild(),
                    calc.getRowType(),
                    builder.getProgram(),
                    calc.getCollationList()));

            // New plan is absolutely better than old plan.
            call.getPlanner().setImportance(calc, 0.0);
          }
        }
Exemple #2
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 /** Returns whether a {@link RexProgram} contains expressions which require decimal expansion. */
 public static boolean requiresDecimalExpansion(RexProgram program, boolean recurse) {
   final List<RexNode> exprList = program.getExprList();
   for (RexNode expr : exprList) {
     if (requiresDecimalExpansion(expr, recurse)) {
       return true;
     }
   }
   return false;
 }
Exemple #3
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 /**
  * Burrows into a synthetic record and returns the underlying relation which provides the field
  * called <code>fieldName</code>.
  */
 public JavaRel implementFieldAccess(JavaRelImplementor implementor, String fieldName) {
   if (!isBoxed()) {
     return implementor.implementFieldAccess((JavaRel) getChild(), fieldName);
   }
   RelDataType type = getRowType();
   int field = type.getFieldOrdinal(fieldName);
   RexLocalRef ref = program.getProjectList().get(field);
   final int index = ref.getIndex();
   return implementor.findRel((JavaRel) this, program.getExprList().get(index));
 }
 /**
  * Determines whether it is possible to implement a set of expressions in Java.
  *
  * @param program Program to translate
  * @return whether all expressions in the program can be implemented
  */
 public boolean canTranslate(RelNode rel, RexProgram program) {
   RexToOJTranslator translator = newTranslator(rel);
   TranslationTester tester = new TranslationTester(translator, true);
   final List<RexNode> exprList = program.getExprList();
   for (RexNode expr : exprList) {
     if (!tester.canTranslate(expr)) {
       return false;
     }
   }
   return true;
 }