private void analyzeCall(RexCall call, Constancy callConstancy) {
      parentCallTypeStack.add(call.getOperator());

      // visit operands, pushing their states onto stack
      super.visitCall(call);

      // look for NON_CONSTANT operands
      int nOperands = call.getOperands().length;
      List<Constancy> operandStack = stack.subList(stack.size() - nOperands, stack.size());
      for (Constancy operandConstancy : operandStack) {
        if (operandConstancy == Constancy.NON_CONSTANT) {
          callConstancy = Constancy.NON_CONSTANT;
        }
      }

      // Even if all operands are constant, the call itself may
      // be non-deterministic.
      if (!call.getOperator().isDeterministic()) {
        callConstancy = Constancy.NON_CONSTANT;
      } else if (call.getOperator().isDynamicFunction()) {
        // We can reduce the call to a constant, but we can't
        // cache the plan if the function is dynamic
        preparingStmt.disableStatementCaching();
      }

      // Row operator itself can't be reduced to a literal, but if
      // the operands are constants, we still want to reduce those
      if ((callConstancy == Constancy.REDUCIBLE_CONSTANT)
          && (call.getOperator() instanceof SqlRowOperator)) {
        callConstancy = Constancy.NON_CONSTANT;
      }

      if (callConstancy == Constancy.NON_CONSTANT) {
        // any REDUCIBLE_CONSTANT children are now known to be maximal
        // reducible subtrees, so they can be added to the result
        // list
        for (int iOperand = 0; iOperand < nOperands; ++iOperand) {
          Constancy constancy = operandStack.get(iOperand);
          if (constancy == Constancy.REDUCIBLE_CONSTANT) {
            addResult(call.getOperands()[iOperand]);
          }
        }

        // if this cast expression can't be reduced to a literal,
        // then see if we can remove the cast
        if (call.getOperator() == SqlStdOperatorTable.castFunc) {
          reduceCasts(call);
        }
      }

      // pop operands off of the stack
      operandStack.clear();

      // pop this parent call operator off the stack
      parentCallTypeStack.remove(parentCallTypeStack.size() - 1);

      // push constancy result for this call onto stack
      stack.add(callConstancy);
    }
示例#2
0
  /** Reconstructs a rex predicate from a list of SargExprs which will be AND'ed together. */
  private void recomposeConjunction() {
    for (int i = 0; i < sargBindingList.size(); i++) {
      final SargBinding currBinding = sargBindingList.get(i);
      final RexInputRef currRef = currBinding.getInputRef();
      SargExpr currSargExpr = currBinding.getExpr();
      RexNode currAndNode = sarg2RexMap.get(currSargExpr);

      // don't need this anymore
      // will be have new mapping put back if currSargExpr remain
      // unchanged.
      sarg2RexMap.remove(currSargExpr);
      boolean recomp = false;

      // search the rest of the list to find SargExpr on the same col.
      ListIterator<SargBinding> iter = sargBindingList.listIterator(i + 1);

      while (iter.hasNext()) {
        final SargBinding nextBinding = iter.next();
        final RexInputRef nextRef = nextBinding.getInputRef();
        final SargExpr nextSargExpr = nextBinding.getExpr();

        if (nextRef.getIndex() == currRef.getIndex()) {
          // build new SargExpr
          SargSetExpr expr =
              factory.newSetExpr(currSargExpr.getDataType(), SargSetOperator.INTERSECTION);
          expr.addChild(currSargExpr);
          expr.addChild(nextSargExpr);

          // build new RexNode
          currAndNode =
              factory
                  .getRexBuilder()
                  .makeCall(
                      SqlStdOperatorTable.andOperator, currAndNode, sarg2RexMap.get(nextSargExpr));

          currSargExpr = expr;

          sarg2RexMap.remove(nextSargExpr);
          iter.remove();

          recomp = true;
        }
      }

      if (recomp) {
        assert !simpleMode;
        if (!testDynamicParamSupport(currSargExpr)) {
          // Oops, we can't actually support the conjunction we
          // recomposed.  Toss it.  (We could do a better job by at
          // least using part of it, but the effort might be better
          // spent on implementing deferred expression evaluation.)
          nonSargFilterList.add(currAndNode);
          sargBindingList.remove(i);
          continue;
        }
      }

      if (recomp) {
        SargBinding newBinding = new SargBinding(currSargExpr, currRef);
        sargBindingList.remove(i);
        sargBindingList.add(i, newBinding);
      }

      sarg2RexMap.put(currSargExpr, currAndNode);
    }
  }