List of updateBestPlanMap() Examples

Examples of updateBestPlanMap()

org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()
When remembering "truly the best" access path for an Optimizable, we have to keep track of which OptimizerImpl the "truly the best" access is for. In most queries there will only be one OptimizerImpl in question, but in cases where there are nested subqueries, there will be one OptimizerImpl for every level of nesting, and each OptimizerImpl might have its own idea of what this Optimizable's "truly the best path" access path really is. In addition, there could be Optimizables above this Optimizable that might need to override the best path chosen during optimization. So whenever we save a "truly the best" path, we take note of which Optimizer/Optimizable told us to do so. Then as each level of subquery finishes optimization, the corresponding OptimizerImpl/Optimizable can load its preferred access path into this Optimizable's trulyTheBestAccessPath field and pass it up the tree, until eventually the outer-most OptimizerImpl can choose to either use the best path that it received from below (by calling "rememberAsBest()") or else use the path that it found to be "best" for itself. This method is what allows us to keep track of which OptimizerImpl or Optimizable saved which "best plan", and allows us to load the appropriate plans after each round of optimization. @param action Indicates whether we're adding, loading, or removinga best plan for the OptimizerImpl/Optimizable. @param planKey Object to use as the map key when adding/looking upa plan. If it is an instance of OptimizerImpl then it corresponds to an outer query; otherwise it's some Optimizable above this Optimizable that could potentially reject plans chosen by the OptimizerImpl to which this Optimizable belongs.

Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

      Optimizable pullMe =
        optimizableList.getOptimizable(
                  proposedJoinOrder[joinPosition]);
      pullMe.pullOptPredicates(predicateList);
      if (reloadBestPlan)
        pullMe.updateBestPlanMap(FromTable.LOAD_PLAN, this);
      proposedJoinOrder[joinPosition] = -1;
      if (joinPosition == 0) break;
    }
    currentCost.setCost(0.0d, 0.0d, 0.0d);
    currentSortAvoidanceCost.setCost(0.0d, 0.0d, 0.0d);

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

    ** because 'reloading best plans' involves walking the
    ** entire subtree of _every_ Optimizable in the list, which
    ** can be expensive if there are deeply nested subqueries.
    */
    if (reloadBestPlan)
      pullMe.updateBestPlanMap(FromTable.LOAD_PLAN, this);


    /* Mark current join position as unused */
    proposedJoinOrder[joinPosition] = -1;


    /* If we didn't advance the join position then the optimizable

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

      // then we know that the most recent access path (represented
      // by "current" access path) was not the best.
      if (curOpt.getBestAccessPath().getCostEstimate().compare(
        curOpt.getCurrentAccessPath().getCostEstimate()) != 0)
      {
        curOpt.updateBestPlanMap(FromTable.LOAD_PLAN, curOpt);
      }
      else if (curOpt.getBestAccessPath().getCostEstimate().rowCount() <
        curOpt.getCurrentAccessPath().getCostEstimate().rowCount())
      {
        // If currentCost and bestCost have the same cost estimate

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

        // If currentCost and bestCost have the same cost estimate
        // but currentCost has been rejected because of memory, we
        // still need to revert the plans.  In this case the row
        // count for currentCost will be greater than the row count
        // for bestCost, so that's what we just checked.
        curOpt.updateBestPlanMap(FromTable.LOAD_PLAN, curOpt);
      }
    }


    /* If we needed to revert plans for curOpt, we just did it above.
     * So we no longer need to keep the previous best plan--and in fact,

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

    /* If we needed to revert plans for curOpt, we just did it above.
     * So we no longer need to keep the previous best plan--and in fact,
     * keeping it can lead to extreme memory usage for very large
     * queries.  So delete the stored plan for curOpt. DERBY-1315.
     */
    curOpt.updateBestPlanMap(FromTable.REMOVE_PLAN, curOpt);


    /*
    ** When all the access paths have been looked at, we know what the
    ** cheapest one is, so remember it.  Only do this if a cost estimate
    ** has been set for the best access path - one will not have been

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

        ** because 'reloading best plans' involves walking the
        ** entire subtree of _every_ Optimizable in the list, which
        ** can be expensive if there are deeply nested subqueries.
        */
        if (reloadBestPlan)
          pullMe.updateBestPlanMap(FromTable.LOAD_PLAN, this);


        /* Mark current join position as unused */
        proposedJoinOrder[joinPosition] = -1;
      }

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

      Optimizable pullMe =
        optimizableList.getOptimizable(
                  proposedJoinOrder[joinPosition]);
      pullMe.pullOptPredicates(predicateList);
      if (reloadBestPlan)
        pullMe.updateBestPlanMap(FromTable.LOAD_PLAN, this);
      proposedJoinOrder[joinPosition] = -1;
      if (joinPosition == 0) break;
    }
    currentCost.setCost(0.0d, 0.0d, 0.0d);
    currentSortAvoidanceCost.setCost(0.0d, 0.0d, 0.0d);

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

      // then we know that the most recent access path (represented
      // by "current" access path) was not the best.
      if (curOpt.getBestAccessPath().getCostEstimate().compare(
        curOpt.getCurrentAccessPath().getCostEstimate()) != 0)
      {
        curOpt.updateBestPlanMap(FromTable.LOAD_PLAN, curOpt);
      }
      else if (curOpt.getBestAccessPath().getCostEstimate().rowCount() <
        curOpt.getCurrentAccessPath().getCostEstimate().rowCount())
      {
        // If currentCost and bestCost have the same cost estimate

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Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

        // If currentCost and bestCost have the same cost estimate
        // but currentCost has been rejected because of memory, we
        // still need to revert the plans.  In this case the row
        // count for currentCost will be greater than the row count
        // for bestCost, so that's what we just checked.
        curOpt.updateBestPlanMap(FromTable.LOAD_PLAN, curOpt);
      }
    }


    /* If we needed to revert plans for curOpt, we just did it above.
     * So we no longer need to keep the previous best plan--and in fact,

View Full Code Here

Examples of org.apache.derby.iapi.sql.compile.Optimizable.updateBestPlanMap()

    /* If we needed to revert plans for curOpt, we just did it above.
     * So we no longer need to keep the previous best plan--and in fact,
     * keeping it can lead to extreme memory usage for very large
     * queries.  So delete the stored plan for curOpt. DERBY-1315.
     */
    curOpt.updateBestPlanMap(FromTable.REMOVE_PLAN, curOpt);


    /*
    ** When all the access paths have been looked at, we know what the
    ** cheapest one is, so remember it.  Only do this if a cost estimate
    ** has been set for the best access path - one will not have been

View Full Code Here

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