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

java.lang.Object
  extended by org.apache.derby.impl.sql.compile.OptimizerFactoryImpl
All Implemented Interfaces:
ModuleControl, OptimizerFactory
Direct Known Subclasses:
Level2OptimizerFactoryImpl

public class OptimizerFactoryImpl
extends java.lang.Object
implements ModuleControl, OptimizerFactory

This is simply the factory for creating an optimizer.


Field Summary
protected  JoinStrategy[] joinStrategySet
           
protected  int maxMemoryPerTable
           
protected  boolean noTimeout
           
protected  java.lang.String optimizerId
           
protected  boolean ruleBasedOptimization
           
protected  boolean useStatistics
           
 
Fields inherited from interface org.apache.derby.iapi.sql.compile.OptimizerFactory
MODULE
 
Constructor Summary
OptimizerFactoryImpl()
           
 
Method Summary
 void boot(boolean create, java.util.Properties startParams)
          Boot this module with the given properties.
 CostEstimate getCostEstimate()
          Return a new CostEstimate.
 int getMaxMemoryPerTable()
          Return the maxMemoryPerTable setting, this is used in optimizer, as well as subquery materialization at run time.
 Optimizer getOptimizer(OptimizableList optimizableList, OptimizablePredicateList predList, DataDictionary dDictionary, RequiredRowOrdering requiredRowOrdering, int numTablesInQuery, LanguageConnectionContext lcc)
          Only one optimizer level should exist in the database, however, the connection may have multiple instances of that optimizer at a given time.
protected  Optimizer getOptimizerImpl(OptimizableList optimizableList, OptimizablePredicateList predList, DataDictionary dDictionary, RequiredRowOrdering requiredRowOrdering, int numTablesInQuery, LanguageConnectionContext lcc)
           
 void stop()
          Stop the module.
 boolean supportsOptimizerTrace()
          Return whether or not the optimizer associated with this factory supports optimizer trace.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

optimizerId

protected java.lang.String optimizerId

ruleBasedOptimization

protected boolean ruleBasedOptimization

noTimeout

protected boolean noTimeout

useStatistics

protected boolean useStatistics

maxMemoryPerTable

protected int maxMemoryPerTable

joinStrategySet

protected JoinStrategy[] joinStrategySet
Constructor Detail

OptimizerFactoryImpl

public OptimizerFactoryImpl()
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
Throws:
StandardException - Module cannot be started.
See Also:
Monitor, ModuleFactory

stop

public void stop()
Description copied from interface: ModuleControl
Stop the module. The module may be found via a findModule() method until some time after this method returns. Therefore the factory must be prepared to reject requests to it once it has been stopped. In addition other modules may cache a reference to the module and make requests of it after it has been stopped, these requests should be rejected as well.

Specified by:
stop in interface ModuleControl
See Also:
Monitor, ModuleFactory

getOptimizer

public Optimizer getOptimizer(OptimizableList optimizableList,
                              OptimizablePredicateList predList,
                              DataDictionary dDictionary,
                              RequiredRowOrdering requiredRowOrdering,
                              int numTablesInQuery,
                              LanguageConnectionContext lcc)
                       throws StandardException
Description copied from interface: OptimizerFactory
Only one optimizer level should exist in the database, however, the connection may have multiple instances of that optimizer at a given time.

Specified by:
getOptimizer in interface OptimizerFactory
Parameters:
optimizableList - The list of Optimizables to optimize.
predList - The list of unassigned OptimizablePredicates.
dDictionary - The DataDictionary to use.
requiredRowOrdering - The required ordering of the rows to come out of the optimized result set
numTablesInQuery - The number of tables in the current query
lcc - The LanguageConnectionContext RESOLVE - We probably want to pass a subquery list, once we define a new interface for them, so that the Optimizer can out where to attach the subqueries.
Throws:
StandardException - Thrown on error
See Also:
OptimizerFactory.getOptimizer(org.apache.derby.iapi.sql.compile.OptimizableList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList, org.apache.derby.iapi.sql.dictionary.DataDictionary, org.apache.derby.iapi.sql.compile.RequiredRowOrdering, int, org.apache.derby.iapi.sql.conn.LanguageConnectionContext)

getCostEstimate

public CostEstimate getCostEstimate()
                             throws StandardException
Description copied from interface: OptimizerFactory
Return a new CostEstimate.

Specified by:
getCostEstimate in interface OptimizerFactory
Throws:
StandardException - Thrown on error
See Also:
OptimizerFactory.getCostEstimate()

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
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
Throws:
StandardException

getMaxMemoryPerTable

public int getMaxMemoryPerTable()
Description copied from interface: OptimizerFactory
Return the maxMemoryPerTable setting, this is used in optimizer, as well as subquery materialization at run time.

Specified by:
getMaxMemoryPerTable in interface OptimizerFactory
Returns:
maxMemoryPerTable value
See Also:
OptimizerFactory.getMaxMemoryPerTable()

Built on Thu 2010-12-23 20:49:13+0000, from revision ???

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