Package se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.costmodel
package se.liu.ida.hefquin.engine.queryproc.impl.poptimizer.costmodel
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ClassDescriptionAbstract base class for implementations of
CostFunctionForRootOp.Generic implementation ofCostFunctionForPlanthat can be used for any cost function that is defined as the sum of operator-specific cost values for all operators in the plan.An implementation ofCostFunctionForPlanthat can be used for any cost function that considers parallelism of operatorsPhysicalOpMultiwayUnion,PhysicalOpBinaryUnionandPhysicalOpSymmetricHashJoin, in which operators, the maximum cost values among subQueries is taken into account.Implementations of this interface represent functions that determine some form of cost value for any given (physical) query plan.Implementations of this interface represent functions that determine some form of cost value for the root node of any given query plan.