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.

         * 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);
        }
      }


      optimizer.trace(Optimizer.COST_OF_CONGLOMERATE_SCAN1,

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      /* initial row count is the row count without applying
         any predicates-- we use this at the end of the routine
         when we use statistics to recompute the row count.
      */
      double initialRowCount = costEstimate.rowCount();


      if (statStartStopSelectivity != 1.0d)
      {
        /*
        ** If statistics exist use the selectivity computed

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        costEstimate.setCost(
               scanCostAfterSelectivity(costEstimate.getEstimatedCost(),
                            initialPositionCost,
                            statStartStopSelectivity,
                            oneRowResultSetForSomeConglom),
               costEstimate.rowCount() * statStartStopSelectivity,
               costEstimate.singleScanRowCount() *
               statStartStopSelectivity);
        optimizer.trace(Optimizer.COST_INCLUDING_STATS_FOR_INDEX,
                tableNumber, 0, 0.0, costEstimate);

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          costEstimate.setCost(
             scanCostAfterSelectivity(costEstimate.getEstimatedCost(),
                          initialPositionCost,
                          extraFirstColumnSelectivity,
                          oneRowResultSetForSomeConglom),
             costEstimate.rowCount() * extraFirstColumnSelectivity,
             costEstimate.singleScanRowCount() * extraFirstColumnSelectivity);
          
          optimizer.trace(Optimizer.COST_INCLUDING_EXTRA_1ST_COL_SELECTIVITY,
                  tableNumber, 0, 0.0, costEstimate);
        }

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


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

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        ** This is also true for join strategies that scan the
        ** inner table only once (like hash join) - we can
        ** tell if we have one of those, because
        ** multiplyBaseCostByOuterRows() will return false.
        */
        double rowsTouched = costEstimate.rowCount();


        if ( (! constantStartStop) &&
           currentJoinStrategy.multiplyBaseCostByOuterRows())
        {
          /*

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          ** locking.
          */
          double r = baseRowCount();
          if (r > 0.0)
          {
            double s = costEstimate.rowCount();
            double o = outerCost.rowCount();
            double pRowsNotTouchedPerScan = 1.0 - (s / r);
            double pRowsNotTouchedAllScans =
                    Math.pow(pRowsNotTouchedPerScan, o);
            double pRowsTouchedAllScans =

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        double singleFetchCost =
            getBaseCostController().getFetchFromRowLocationCost(
                                (FormatableBitSet) null,
                                0);


        cost = singleFetchCost * costEstimate.rowCount();


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


        optimizer.trace(Optimizer.COST_OF_NONCOVERING_INDEX,

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       */
      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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