Class OptimizerFactoryImpl

java.lang.Object
org.apache.derby.impl.sql.compile.OptimizerFactoryImpl
All Implemented Interfaces:
ModuleControl, OptimizerFactory

public class OptimizerFactoryImpl extends Object implements ModuleControl, OptimizerFactory
This is simply the factory for creating an optimizer.
  • Field Details

    • optimizerId

      protected String optimizerId
    • ruleBasedOptimization

      protected boolean ruleBasedOptimization
    • noTimeout

      protected boolean noTimeout
    • useStatistics

      protected boolean useStatistics
    • maxMemoryPerTable

      protected int maxMemoryPerTable
    • joinStrategySet

      protected JoinStrategy[] joinStrategySet
    • joinOrderOptimization

      private boolean joinOrderOptimization
  • Constructor Details

    • OptimizerFactoryImpl

      public OptimizerFactoryImpl()
  • Method Details

    • boot

      public void boot(boolean create, 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:
    • 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:
    • getOptimizer

      public Optimizer getOptimizer(OptimizableList optimizableList, OptimizablePredicateList predList, DataDictionary dDictionary, RequiredRowOrdering requiredRowOrdering, int numTablesInQuery, OptimizerPlan overridingPlan, 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
      overridingPlan - (Optional) A complete plan specified by optimizer overrides. Must have been bound already.
      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:
    • getCostEstimate

      public CostEstimate getCostEstimate()
      Description copied from interface: OptimizerFactory
      Return a new CostEstimate.
      Specified by:
      getCostEstimate in interface OptimizerFactory
      See Also:
    • 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:
    • getOptimizerImpl

      protected Optimizer getOptimizerImpl(OptimizableList optimizableList, OptimizablePredicateList predList, DataDictionary dDictionary, RequiredRowOrdering requiredRowOrdering, int numTablesInQuery, OptimizerPlan overridingPlan, 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:
    • doJoinOrderOptimization

      public boolean doJoinOrderOptimization()
      Description copied from interface: OptimizerFactory
      Tell whether to do join order optimization.
      Specified by:
      doJoinOrderOptimization in interface OptimizerFactory
      Returns:
      true means do join order optimization, false means don't do it.