示例#1
0
  /**
   * Tests whether we can support the usage of dynamic parameters in a given SargExpr.
   *
   * @param sargExpr expression to test
   * @return true if supported
   */
  private boolean testDynamicParamSupport(SargExpr sargExpr) {
    // NOTE jvs 18-Mar-2006: we don't currently support boolean operators
    // over predicates on dynamic parameters.  The reason is that we
    // evaluate sarg expressions at prepare time rather than at execution
    // time.  To support them, we would need a way to defer evaluation
    // until execution time (Broadbase used to do that).

    Set<RexDynamicParam> dynamicParams = new HashSet<RexDynamicParam>();
    sargExpr.collectDynamicParams(dynamicParams);
    if (dynamicParams.isEmpty()) {
      // no dynamic params, no problem
      return true;
    }
    if (sargExpr instanceof SargIntervalExpr) {
      // We can support a single point or ray, which is the
      // most that would have been generated by the time this is
      // called.  Should probably assert that.
      return true;
    }

    // Anything else is unsupported.
    return false;
  }
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);
    }
  }