Examples of org.apache.derby.iapi.sql.compile.CostEstimate.rowCount()

Package org.apache.derby.iapi.sql.compile

Class org.apache.derby.iapi.sql.compile.CostEstimate

Examples of org.apache.derby.iapi.sql.compile.CostEstimate.rowCount()

org.apache.derby.iapi.sql.compile.CostEstimate.rowCount()
Get the estimated number of rows returned by the ResultSet that this CostEstimate models.

       */
      if (extraQualifierSelectivity != 1.0d)
      {
        costEstimate.setCost(
            costEstimate.getEstimatedCost(),
            costEstimate.rowCount() * extraQualifierSelectivity,
            costEstimate.singleScanRowCount() * extraQualifierSelectivity);


        optimizer.trace(Optimizer.COST_INCLUDING_EXTRA_QUALIFIER_SELECTIVITY,
                tableNumber, 0, 0.0, costEstimate);
      }

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      ** conglomerate is a 1 row result set when costing nested
      ** loop.  (eg, we will find at most 1 match when probing
      ** the hash table.)
      */
      double newCost = costEstimate.getEstimatedCost();
      double rowCount = costEstimate.rowCount();


      /*
      ** RESOLVE - If there is a unique index on the joining
      ** columns, the number of matching rows will equal the
      ** number of outer rows, even if we're not considering the

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      // don't factor in extraNonQualifierSelectivity in case of oneRowResultSetForSomeConglom
      // because "1" is the final result and the effect of other predicates already considered
      // beetle 4787
      else if (extraNonQualifierSelectivity != 1.0d)
      {
        rc = oneRowResultSetForSomeConglom ? costEstimate.rowCount() :
                      costEstimate.rowCount() * extraNonQualifierSelectivity;
        src = costEstimate.singleScanRowCount() * extraNonQualifierSelectivity;
      }
      if (rc != -1) // changed
      {

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      // because "1" is the final result and the effect of other predicates already considered
      // beetle 4787
      else if (extraNonQualifierSelectivity != 1.0d)
      {
        rc = oneRowResultSetForSomeConglom ? costEstimate.rowCount() :
                      costEstimate.rowCount() * extraNonQualifierSelectivity;
        src = costEstimate.singleScanRowCount() * extraNonQualifierSelectivity;
      }
      if (rc != -1) // changed
      {
        costEstimate.setCost(costEstimate.getEstimatedCost(), rc, src);

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    CostEstimate rightCE = rightResultSet.getFinalCostEstimate();


    finalCostEstimate = getNewCostEstimate();
    finalCostEstimate.setCost(
      leftCE.getEstimatedCost() + rightCE.getEstimatedCost(),
      rightCE.rowCount(),
      rightCE.rowCount());


    return finalCostEstimate;
  }

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    finalCostEstimate = getNewCostEstimate();
    finalCostEstimate.setCost(
      leftCE.getEstimatedCost() + rightCE.getEstimatedCost(),
      rightCE.rowCount(),
      rightCE.rowCount());


    return finalCostEstimate;
  }


  protected void oneRowRightSide(ActivationClassBuilder acb,

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        newCost *= outerCost.rowCount();
      }


      costEstimate.setCost(
        newCost,
        costEstimate.rowCount() * outerCost.rowCount(),
        costEstimate.singleScanRowCount());


      /*
      ** Choose the lock mode.  If the start/stop conditions are
      ** constant, choose row locking, because we will always match

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        optimizer.trace(Optimizer.ROW_LOCK_ALL_CONSTANT_START_STOP,
                0, 0, 0.0, null);
      }
      else
      {
        setLockingBasedOnThreshold(optimizer, costEstimate.rowCount());
      }


      optimizer.trace(Optimizer.COST_OF_N_SCANS, 
              tableNumber, 0, outerCost.rowCount(), costEstimate);

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      {
        double singleFetchCost =
            getBaseCostController().getFetchFromRowLocationCost(
                                (FormatableBitSet) null,
                                0);
        cost = singleFetchCost * costEstimate.rowCount();


        costEstimate.setEstimatedCost(
                costEstimate.getEstimatedCost() + cost);


        optimizer.trace(Optimizer.NON_COVERING_INDEX_COST,

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         * won't return any row or just returns one row (eg., the predicate is a
         * comparison with constant or almost empty table), we do minor adjustment
         * on cost (affecting decision for covering index) and rc (decision for
         * non-covering). The purpose is favoring unique index. beetle 5006.
         */
        if (oneRowResultSetForSomeConglom && costEstimate.rowCount() <= 1)
        {
          costEstimate.setCost(costEstimate.getEstimatedCost() * 2,
                     costEstimate.rowCount() + 2,
                     costEstimate.singleScanRowCount() + 2);
        }

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