org.apache.derby.impl.sql.compile

Class Level2OptimizerFactoryImpl

java.lang.Object

org.apache.derby.impl.sql.compile.OptimizerFactoryImpl

org.apache.derby.impl.sql.compile.Level2OptimizerFactoryImpl

All Implemented Interfaces:

ModuleControl, OptimizerFactory

public class Level2OptimizerFactoryImpl
extends OptimizerFactoryImpl

This is simply the factory for creating an optimizer.

Field Summary

Fields inherited from class org.apache.derby.impl.sql.compile.OptimizerFactoryImpl

joinStrategySet, maxMemoryPerTable, noTimeout, optimizerId, ruleBasedOptimization, useStatistics

Fields inherited from interface org.apache.derby.iapi.sql.compile.OptimizerFactory

MODULE

Constructor Summary

Constructors

Constructor and Description
Level2OptimizerFactoryImpl()

Method Summary

Methods

Modifier and Type	Method and Description
void	boot(boolean create, java.util.Properties startParams) Boot this module with the given properties.
CostEstimate	getCostEstimate() Return a new CostEstimate.
protected Optimizer	getOptimizerImpl(OptimizableList optimizableList, OptimizablePredicateList predList, DataDictionary dDictionary, RequiredRowOrdering requiredRowOrdering, int numTablesInQuery, LanguageConnectionContext lcc)
boolean	supportsOptimizerTrace() Return whether or not the optimizer associated with this factory supports optimizer trace.

Methods inherited from class org.apache.derby.impl.sql.compile.OptimizerFactoryImpl

getMaxMemoryPerTable, getOptimizer, stop

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Level2OptimizerFactoryImpl

public Level2OptimizerFactoryImpl()

Method Detail

boot

public void boot(boolean create,
        java.util.Properties startParams)
          throws StandardException

Description copied from interface: ModuleControl

Boot this module with the given properties. Creates a module instance that can be found using the findModule() methods of Monitor. The module can only be found using one of these findModule() methods once this method has returned.

An implementation's boot method can throw StandardException. If it is thrown the module is not registered by the monitor and therefore cannot be found through a findModule(). In this case the module's stop() method is not called, thus throwing this exception must free up any resources.

When create is true the contents of the properties object will be written to the service.properties of the persistent service. Thus any code that requires an entry in service.properties must explicitly place the value in this properties set using the put method.
Typically the properties object contains one or more default properties sets, which are not written out to service.properties. These default sets are how callers modify the create process. In a JDBC connection database create the first set of defaults is a properties object that contains the attributes that were set on the jdbc:derby: URL. This attributes properties set has the second default properties set as its default. This set (which could be null) contains the properties that the user set on their DriverManager.getConnection() call, and are thus not owned by Derby code, and thus must not be modified by Derby code.

When create is false the properties object contains all the properties set in the service.properties file plus a limited number of attributes from the JDBC URL attributes or connection properties set. This avoids properties set by the user compromising the boot process. An example of a property passed in from the JDBC world is the bootPassword for encrypted databases.

Code should not hold onto the passed in properties reference after boot time as its contents may change underneath it. At least after the complete boot is completed, the links to all the default sets will be removed.

Specified by:

boot in interface ModuleControl

Overrides:

boot in class OptimizerFactoryImpl

Throws:

StandardException - Module cannot be started.

See Also:

Monitor, ModuleFactory

supportsOptimizerTrace

public boolean supportsOptimizerTrace()

Description copied from interface: OptimizerFactory

Return whether or not the optimizer associated with this factory supports optimizer trace.

Specified by:

supportsOptimizerTrace in interface OptimizerFactory

Overrides:

supportsOptimizerTrace in class OptimizerFactoryImpl

Returns:

Whether or not the optimizer associated with this factory supports optimizer trace.

See Also:

OptimizerFactory.supportsOptimizerTrace()

getOptimizerImpl

protected Optimizer getOptimizerImpl(OptimizableList optimizableList,
                         OptimizablePredicateList predList,
                         DataDictionary dDictionary,
                         RequiredRowOrdering requiredRowOrdering,
                         int numTablesInQuery,
                         LanguageConnectionContext lcc)
                              throws StandardException

Overrides:

getOptimizerImpl in class OptimizerFactoryImpl

Throws:

StandardException

getCostEstimate

public CostEstimate getCostEstimate()
                             throws StandardException

Description copied from interface: OptimizerFactory

Return a new CostEstimate.

Specified by:

getCostEstimate in interface OptimizerFactory

Overrides:

getCostEstimate in class OptimizerFactoryImpl

Throws:

StandardException - Thrown on error

See Also:

OptimizerFactory.getCostEstimate()