public Class OptimizerFactoryImpl

Implements org.apache.derby.iapi.services.monitor.ModuleControl.boot.

Doc from org.apache.derby.iapi.services.monitor.ModuleControl.boot.

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.

Parameters

create:boolean

True if the database should be created

startParams:Properties

Configuration properties

Exceptions

StandardException:

Module cannot be started.

Implements org.apache.derby.iapi.sql.compile.OptimizerFactory.doJoinOrderOptimization.

Doc from org.apache.derby.iapi.sql.compile.OptimizerFactory.doJoinOrderOptimization.

Tell whether to do join order optimization.

Returns:boolean

true means do join order optimization, false means don't do it.

Annotations

@Override

Implements org.apache.derby.iapi.sql.compile.OptimizerFactory.getCostEstimate.

Doc from org.apache.derby.iapi.sql.compile.OptimizerFactory.getCostEstimate.

Return a new CostEstimate.

See Also

OptimizerFactory#getCostEstimate

Implements org.apache.derby.iapi.sql.compile.OptimizerFactory.getMaxMemoryPerTable.

Doc from org.apache.derby.iapi.sql.compile.OptimizerFactory.getMaxMemoryPerTable.

Return the maxMemoryPerTable setting, this is used in optimizer, as well as subquery materialization at run time.

Returns:int

maxMemoryPerTable value

See Also

OptimizerFactory#getMaxMemoryPerTable

Implements org.apache.derby.iapi.sql.compile.OptimizerFactory.getOptimizer.

Doc from org.apache.derby.iapi.sql.compile.OptimizerFactory.getOptimizer.

Only one optimizer level should exist in the database, however, the connection may have multiple instances of that optimizer at a given time.

Parameters

optimizableList:OptimizableList

The list of Optimizables to optimize.

predList:OptimizablePredicateList

The list of unassigned OptimizablePredicates.

dDictionary:DataDictionary

The DataDictionary to use.

requiredRowOrdering:RequiredRowOrdering

The required ordering of the rows to come out of the optimized result set

numTablesInQuery:int

The number of tables in the current query

overridingPlan:OptimizerPlan

(Optional) A complete plan specified by optimizer overrides. Must have been bound already.

lcc:LanguageConnectionContext

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.

Exceptions

StandardException:

Thrown on error

See Also

OptimizerFactory#getOptimizer

Implements org.apache.derby.iapi.services.monitor.ModuleControl.stop.

Doc from org.apache.derby.iapi.services.monitor.ModuleControl.stop.

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.

Implements org.apache.derby.iapi.sql.compile.OptimizerFactory.supportsOptimizerTrace.

Doc from org.apache.derby.iapi.sql.compile.OptimizerFactory.supportsOptimizerTrace.

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

Returns:boolean

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

See Also

OptimizerFactory#supportsOptimizerTrace