Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.store.access.sort.ExternalSortFactory

Modifier and Type	Field and Description
protected static final int	DEFAULT_MAX_MERGE_RUN
protected static final int	DEFAULT_MEM_USE
private static final int	DEFAULT_SORTBUFFERMAX
private int	defaultSortBufferMax
private UUID	formatUUID
private static final String	FORMATUUIDSTRING
private static final String	IMPLEMENTATIONID
private static final int	MINIMUM_SORTBUFFERMAX
private static final int	SORT_ROW_OVERHEAD
private int	sortBufferMax
private boolean	userSpecified

Access	Constructor and Description
public	ExternalSortFactory()

Method Summary

Modifier and Type	Method and Description
public void	boot(boolean True if the database should be created create, Properties Configuration properties startParams) Implements org.apache.derby.iapi.services.monitor.ModuleControl.boot. Boot this module with the given properties.
public boolean	canSupport(Properties startParams) Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport. See if this implementation can support any attributes that are listed in properties.
public void	close() Implements org.apache.derby.iapi.store.access.SortCostController.close. Close the controller.
public Sort	createSort(TransactionController tran, int segment, Properties implParameters, DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int estimatedRowSize) Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.createSort. Create a sort.
public Properties	defaultProperties() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.defaultProperties. There are no default properties for the external sort..
protected MergeSort	Returns: MergeSort implementation getMergeSort() Returns merge sort implementation.
private static ModuleFactory	getMonitor() Must be private so that user code can't call this entry point.
public double	Returns: The identifier to be used to open the conglomerate later. getSortCost(DataValueDescriptor[] A row which is prototypical for the sort. All rows inserted into the sort controller must have exactly the same number of columns as the template row. Every column in an inserted row must have the same type as the corresponding column in the template. template, ColumnOrdering[] An array which specifies which columns participate in ordering - see interface ColumnOrdering for details. The column referenced in the 0th columnOrdering object is compared first, then the 1st, etc. columnOrdering, boolean Indicates that the rows inserted into the sort controller will already be in order. This is used to perform aggregation only. alreadyInOrder, long The number of rows that the caller estimates will be inserted into the sort. This number must be >= 0. estimatedInputRows, long The number of rows that the caller estimates will be exported by the sorter. For instance if the sort is doing duplicate elimination and all rows are expected to be duplicates then the estimatedExportRows would be 1. If no duplicate eliminate is to be done then estimatedExportRows would be the same as estimatedInputRows. This number must be >= 0. estimatedExportRows, int The estimated average row size of the rows being sorted. This is the client portion of the rowsize, it should not attempt to calculate Store's overhead. -1 indicates that the caller has no idea (and the sorter will use 100 bytes in that case. Used by the sort to make good choices about in-memory vs. external sorting, and to size merge runs. The client is not expected to estimate the per column/ per row overhead of raw store, just to make a guess about the storage associated with each row (ie. reasonable estimates for some implementations would be 4 for int, 8 for long, 102 for char(100), 202 for varchar(200), a number out of hat for user types, ...). estimatedRowSize) Implements org.apache.derby.iapi.store.access.SortCostController.getSortCost. Short one line description of routine.
public SortCostController	Returns: The open SortCostController. openSortCostController() Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.openSortCostController. Return an open SortCostController.
public UUID	primaryFormat() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryFormat. Return the primary format that this access method supports.
public String	primaryImplementationType() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryImplementationType. Return the primary implementation type for this access method.
public void	stop() Implements org.apache.derby.iapi.services.monitor.ModuleControl.stop. Stop the module.
public boolean	supportsFormat(UUID formatid) Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsFormat. Return whether this access method supports the format supplied in the argument.
public boolean	supportsImplementation(String implementationId) Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsImplementation. Return whether this access method implements the implementation type given in the argument string.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

DEFAULT_MAX_MERGE_RUN	back to summary
protected static final int DEFAULT_MAX_MERGE_RUN

DEFAULT_MEM_USE	back to summary
protected static final int DEFAULT_MEM_USE

DEFAULT_SORTBUFFERMAX	back to summary
private static final int DEFAULT_SORTBUFFERMAX

defaultSortBufferMax	back to summary
private int defaultSortBufferMax

formatUUID	back to summary
private UUID formatUUID

FORMATUUIDSTRING	back to summary
private static final String FORMATUUIDSTRING

IMPLEMENTATIONID	back to summary
private static final String IMPLEMENTATIONID

MINIMUM_SORTBUFFERMAX	back to summary
private static final int MINIMUM_SORTBUFFERMAX

SORT_ROW_OVERHEAD	back to summary
private static final int SORT_ROW_OVERHEAD

sortBufferMax	back to summary
private int sortBufferMax

userSpecified	back to summary
private boolean userSpecified

ExternalSortFactory	back to summary
public ExternalSortFactory()

Method Detail

boot	back to summary
public void boot(boolean create, Properties startParams) throws StandardException 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.

boot

back to summary

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

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.

canSupport	back to summary
public boolean canSupport(Properties startParams) Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport. Doc from org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport. See if this implementation can support any attributes that are listed in properties. This call may be made on a newly created instance before the boot() method has been called, or after the boot method has been called for a running module. The module can check for attributes in the properties to see if it can fulfill the required behaviour. E.g. the raw store may define an attribute called RawStore.Recoverable. If a temporary raw store is required the property RawStore.recoverable=false would be added to the properties before calling bootServiceModule. If a raw store cannot support this attribute its canSupport method would return null. Also see the Monitor class's prologue to see how the identifier is used in looking up properties. Actually a better way maybe to have properties of the form RawStore.Attributes.mandatory=recoverable,smallfootprint and RawStore.Attributes.requested=oltp,fast Returns:boolean true if this instance can be used, false otherwise.

canSupport

back to summary

public boolean canSupport(Properties startParams)

Implements org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport.

Doc from org.apache.derby.iapi.services.monitor.ModuleSupportable.canSupport.

See if this implementation can support any attributes that are listed in properties. This call may be made on a newly created instance before the boot() method has been called, or after the boot method has been called for a running module.

The module can check for attributes in the properties to see if it can fulfill the required behaviour. E.g. the raw store may define an attribute called RawStore.Recoverable. If a temporary raw store is required the property RawStore.recoverable=false would be added to the properties before calling bootServiceModule. If a raw store cannot support this attribute its canSupport method would return null. Also see the Monitor class's prologue to see how the identifier is used in looking up properties.
Actually a better way maybe to have properties of the form RawStore.Attributes.mandatory=recoverable,smallfootprint and RawStore.Attributes.requested=oltp,fast

Returns:boolean: true if this instance can be used, false otherwise.

close	back to summary
public void close() Implements org.apache.derby.iapi.store.access.SortCostController.close. Doc from org.apache.derby.iapi.store.access.SortCostController.close. Close the controller. Close the open controller. This method always succeeds, and never throws any exceptions. Callers must not use the StoreCostController after closing it; they are strongly advised to clear out the StoreCostController reference after closing.

back to summary

public void close()

Implements org.apache.derby.iapi.store.access.SortCostController.close.

Doc from org.apache.derby.iapi.store.access.SortCostController.close.

Close the controller.

Close the open controller. This method always succeeds, and never throws any exceptions. Callers must not use the StoreCostController after closing it; they are strongly advised to clear out the StoreCostController reference after closing.

createSort back to summary

createSort	back to summary
public Sort createSort(TransactionController tran, int segment, Properties implParameters, DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int estimatedRowSize) throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.createSort. Create a sort. This method could choose among different sort options, depending on the properties etc., but currently it always returns a merge sort. Exceptions StandardException: Doc from org.apache.derby.iapi.store.access.conglomerate.SortFactory.createSort. if the sort could not be opened for some reason, or if an error occurred in one of the lower level modules. See Also `SortFactory#createSort`

public Sort createSort(TransactionController tran, int segment, Properties implParameters, DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, SortObserver sortObserver, boolean alreadyInOrder, long estimatedRows, int estimatedRowSize) throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.createSort.

Create a sort. This method could choose among different sort options, depending on the properties etc., but currently it always returns a merge sort.

Exceptions

StandardException:

Doc from org.apache.derby.iapi.store.access.conglomerate.SortFactory.createSort.

if the sort could not be opened for some reason, or if an error occurred in one of the lower level modules.

See Also

SortFactory#createSort

defaultProperties back to summary

defaultProperties	back to summary
public Properties defaultProperties() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.defaultProperties. There are no default properties for the external sort.. See Also `MethodFactory#defaultProperties`

public Properties defaultProperties()

Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.defaultProperties.

There are no default properties for the external sort..

See Also: MethodFactory#defaultProperties

getMergeSort	back to summary
protected MergeSort getMergeSort() Returns merge sort implementation. Extending classes can overide this method to customize sorting. Returns:MergeSort MergeSort implementation

getMergeSort

back to summary

protected MergeSort getMergeSort()

Returns merge sort implementation. Extending classes can overide this method to customize sorting.

Returns:MergeSort: MergeSort implementation

getMonitor	back to summary
private static ModuleFactory getMonitor() Must be private so that user code can't call this entry point.

getSortCost	back to summary
public double getSortCost(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, boolean alreadyInOrder, long estimatedInputRows, long estimatedExportRows, int estimatedRowSize) throws StandardException Implements org.apache.derby.iapi.store.access.SortCostController.getSortCost. Short one line description of routine. The sort algorithm is a N * log(N) algorithm. The following numbers on a PII, 400 MHZ machine, jdk117 with jit, insane.zip. This test is a simple "select * from table order by first_int_column. I then subtracted the time it takes to do "select * from table" from the result. number of rows elaspsed time in seconds -------------- ----------------------------- 1000 0.20 10000 10.5 100000 80.0 We assume that the formula for sort performance is of the form: performance = K * N * log(N). Solving the equation for the 1000 and 100000 case we come up with: performance = 1 + 0.08 N ln(n) Note Apparently, these measurements were done on a faster machine than was used for other performance measurements used by the optimizer. Experiments show that the 0.8 multiplier is off by a factor of 4 with respect to other measurements (such as the time it takes to scan a conglomerate). I am correcting the formula to use 0.32 rather than 0.08. - Jeff RESOLVE (mikem) - this formula is very crude at the moment and will be refined later. known problems: 1) internal vs. external sort - we know that the performance of sort is discontinuous when we go from an internal to an external sort. A better model is probably a different set of contants for internal vs. external sort and some way to guess when this is going to happen. 2) current row size is never considered but is critical to performance. 3) estimatedExportRows is not used. This is a critical number to know if an internal vs. an external sort will happen. Parameters template:DataValueDescriptor[] Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. A row which is prototypical for the sort. All rows inserted into the sort controller must have exactly the same number of columns as the template row. Every column in an inserted row must have the same type as the corresponding column in the template. columnOrdering:ColumnOrdering[] Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. An array which specifies which columns participate in ordering - see interface ColumnOrdering for details. The column referenced in the 0th columnOrdering object is compared first, then the 1st, etc. alreadyInOrder:boolean Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. Indicates that the rows inserted into the sort controller will already be in order. This is used to perform aggregation only. estimatedInputRows:long Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. The number of rows that the caller estimates will be inserted into the sort. This number must be >= 0. estimatedExportRows:long Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. The number of rows that the caller estimates will be exported by the sorter. For instance if the sort is doing duplicate elimination and all rows are expected to be duplicates then the estimatedExportRows would be 1. If no duplicate eliminate is to be done then estimatedExportRows would be the same as estimatedInputRows. This number must be >= 0. estimatedRowSize:int Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost. The estimated average row size of the rows being sorted. This is the client portion of the rowsize, it should not attempt to calculate Store's overhead. -1 indicates that the caller has no idea (and the sorter will use 100 bytes in that case. Used by the sort to make good choices about in-memory vs. external sorting, and to size merge runs. The client is not expected to estimate the per column/ per row overhead of raw store, just to make a guess about the storage associated with each row (ie. reasonable estimates for some implementations would be 4 for int, 8 for long, 102 for char(100), 202 for varchar(200), a number out of hat for user types, ...). Returns:double The identifier to be used to open the conglomerate later. Exceptions StandardException: Standard exception policy.

getSortCost

back to summary

public double getSortCost(DataValueDescriptor[] template, ColumnOrdering[] columnOrdering, boolean alreadyInOrder, long estimatedInputRows, long estimatedExportRows, int estimatedRowSize) throws StandardException

Implements org.apache.derby.iapi.store.access.SortCostController.getSortCost.

Short one line description of routine.

The sort algorithm is a N * log(N) algorithm. The following numbers on a PII, 400 MHZ machine, jdk117 with jit, insane.zip. This test is a simple "select * from table order by first_int_column. I then subtracted the time it takes to do "select * from table" from the result. number of rows elaspsed time in seconds -------------- ----------------------------- 1000 0.20 10000 10.5 100000 80.0 We assume that the formula for sort performance is of the form: performance = K * N * log(N). Solving the equation for the 1000 and 100000 case we come up with: performance = 1 + 0.08 N ln(n)

Note

Apparently, these measurements were done on a faster machine than was used for other performance measurements used by the optimizer. Experiments show that the 0.8 multiplier is off by a factor of 4 with respect to other measurements (such as the time it takes to scan a conglomerate). I am correcting the formula to use 0.32 rather than 0.08. - Jeff

RESOLVE (mikem) - this formula is very crude at the moment and will be refined later. known problems: 1) internal vs. external sort - we know that the performance of sort is discontinuous when we go from an internal to an external sort. A better model is probably a different set of contants for internal vs. external sort and some way to guess when this is going to happen. 2) current row size is never considered but is critical to performance. 3) estimatedExportRows is not used. This is a critical number to know if an internal vs. an external sort will happen.

Parameters

template:DataValueDescriptor[]

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

A row which is prototypical for the sort. All rows inserted into the sort controller must have exactly the same number of columns as the template row. Every column in an inserted row must have the same type as the corresponding column in the template.

columnOrdering:ColumnOrdering[]

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

An array which specifies which columns participate in ordering - see interface ColumnOrdering for details. The column referenced in the 0th columnOrdering object is compared first, then the 1st, etc.

alreadyInOrder:boolean

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

Indicates that the rows inserted into the sort controller will already be in order. This is used to perform aggregation only.

estimatedInputRows:long

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

The number of rows that the caller estimates will be inserted into the sort. This number must be >= 0.

estimatedExportRows:long

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

The number of rows that the caller estimates will be exported by the sorter. For instance if the sort is doing duplicate elimination and all rows are expected to be duplicates then the estimatedExportRows would be 1. If no duplicate eliminate is to be done then estimatedExportRows would be the same as estimatedInputRows. This number must be >= 0.

estimatedRowSize:int

Doc from org.apache.derby.iapi.store.access.SortCostController.getSortCost.

The estimated average row size of the rows being sorted. This is the client portion of the rowsize, it should not attempt to calculate Store's overhead. -1 indicates that the caller has no idea (and the sorter will use 100 bytes in that case. Used by the sort to make good choices about in-memory vs. external sorting, and to size merge runs. The client is not expected to estimate the per column/ per row overhead of raw store, just to make a guess about the storage associated with each row (ie. reasonable estimates for some implementations would be 4 for int, 8 for long, 102 for char(100), 202 for varchar(200), a number out of hat for user types, ...).

Returns:double

The identifier to be used to open the conglomerate later.

Exceptions

StandardException:: Standard exception policy.

openSortCostController back to summary

openSortCostController	back to summary
public SortCostController openSortCostController() throws StandardException Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.openSortCostController. Return an open SortCostController. Return an open SortCostController which can be used to ask about the estimated costs of SortController() operations. Returns:SortCostController The open SortCostController. Exceptions StandardException: Standard exception policy. See Also `SortCostController`

public SortCostController openSortCostController() throws StandardException

Implements org.apache.derby.iapi.store.access.conglomerate.SortFactory.openSortCostController.

Return an open SortCostController.

Return an open SortCostController which can be used to ask about the estimated costs of SortController() operations.

Returns:SortCostController

The open SortCostController.

Exceptions

StandardException:: Standard exception policy.

See Also

SortCostController

primaryFormat back to summary

primaryFormat	back to summary
public UUID primaryFormat() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryFormat. Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryFormat. Return the primary format that this access method supports. Although an access method may support more than one format, this is the usual one. the access manager will put the primary format in a hash table for fast access to the appropriate method. See Also `MethodFactory#primaryFormat`

public UUID primaryFormat()

Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryFormat.

Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryFormat.

Return the primary format that this access method supports. Although an access method may support more than one format, this is the usual one. the access manager will put the primary format in a hash table for fast access to the appropriate method.

See Also: MethodFactory#primaryFormat

primaryImplementationType back to summary

primaryImplementationType	back to summary
public String primaryImplementationType() Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryImplementationType. Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryImplementationType. Return the primary implementation type for this access method. Although an access method may implement more than one implementation type, this is the expected one. The access manager will put the primary implementation type in a hash table for fast access. See Also `MethodFactory#primaryImplementationType`

public String primaryImplementationType()

Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryImplementationType.

Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.primaryImplementationType.

Return the primary implementation type for this access method. Although an access method may implement more than one implementation type, this is the expected one. The access manager will put the primary implementation type in a hash table for fast access.

See Also: MethodFactory#primaryImplementationType

stop	back to summary
public void stop() 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.

stop

back to summary

public void stop()

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.

supportsFormat back to summary

supportsFormat	back to summary
public boolean supportsFormat(UUID formatid) Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsFormat. Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsFormat. Return whether this access method supports the format supplied in the argument. See Also `MethodFactory#supportsFormat`

public boolean supportsFormat(UUID formatid)

Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsFormat.

Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsFormat.

Return whether this access method supports the format supplied in the argument.

See Also: MethodFactory#supportsFormat

supportsImplementation back to summary

supportsImplementation	back to summary
public boolean supportsImplementation(String implementationId) Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsImplementation. Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsImplementation. Return whether this access method implements the implementation type given in the argument string. See Also `MethodFactory#supportsImplementation`

public boolean supportsImplementation(String implementationId)

Implements org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsImplementation.

Doc from org.apache.derby.iapi.store.access.conglomerate.MethodFactory.supportsImplementation.

Return whether this access method implements the implementation type given in the argument string.

See Also: MethodFactory#supportsImplementation

public Class ExternalSortFactory

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail