oracle.toplink.sequencing
Interface SequencingControl

public interface SequencingControl

Purpose: Define an interface to control sequencing functionality.

Description: This interface is accessed through DatabaseSession.getSequencingControl(). It allows to create, re-create, customize Sequencing object which is available through DatabaseSession.getSequencing() and provides sequencing values for all descriptors that use sequencing. Here's the lifecycle of Sequencing object used by DatabaseSession: 1. DatabaseSession created - sequencing object doesn't yet exist; 2. DatabaseSession.login() causes creation of Sequencing object; 3. DatabaseSession.logout() causes destruction of Sequencing object. In case sequencing object doesn't yet exist all the set parameters' values will be used during its creation. In case sequencing object already exists: 1. The following methods don't alter sequencing object - the corresponding parameters will only be used in case a new sequencing object is created: setShouldUseSeparateConnection; setLogin; setMinPoolSize; setMaxPoolSize. 2. The following methods cause immediate destruction of the sequencing object and creation of a new one: setValueGenerationPolicy; setShouldUseNativeSequencing; setShouldUseTableSequencing; resetSequencing; 3. The following methods cause change immediately: setPreallocationSize (next sequencing preallocation will use the set parameter's value).

Responsibilities:

• Define the APIs for controlling sequencing.

See Also:

SequencingValueGenerationPolicy, DatabaseSession

Method Summary

DatabaseLogin	getLogin() ADVANCED: Return a DatabaseLogin to be used by separate sequencing connection(s).
int	getMaxPoolSize() PUBLIC: Returns a maximum number of connections in sequencing connection pool
int	getMinPoolSize() PUBLIC: Returns a minimum number of connections in sequencing connection pool.
int	getPreallocationSize() PUBLIC: Returns a number of new sequencing objects to be obtained at a time.
SequencingValueGenerationPolicy	getValueGenerationPolicy() ADVANCED: Retun currently used sequencing value generation policy.
void	initializePreallocated() ADVANCED: Removes all preallocated sequencing objects.
boolean	isConnectedUsingSeparateConnection() PUBLIC: Indicates whether sequencing actually uses separate connection(s).
void	resetSequencing() ADVANCED: Immediately re-create sequencing object.
void	setLogin(DatabaseLogin login) ADVANCED: Returns a DatabaseLogin to be used by separate sequencing connection(s) The set value is ignored if shouldUseSeparateConnection() returns false.
void	setMaxPoolSize(int size) PUBLIC: Sets a maximum number of connections in sequencing connection pool The set value is ignored if shouldUseSeparateConnection() returns false.
void	setMinPoolSize(int size) PUBLIC: Sets a minimum number of connections in sequencing connection pool The set value is ignored if shouldUseSeparateConnection() returns false.
void	setPreallocationSize(int size) PUBLIC: Sets a number of new sequencing objects to be obtained at a time.
void	setShouldUseSeparateConnection(boolean shouldUseSeparateConnection) PUBLIC: Set whether separate connection(s) for sequencing could be used (by default it couldn't).
void	setValueGenerationPolicy(SequencingValueGenerationPolicy policy) ADVANCED: Set sequencing value generation policy.
void	shouldUseNativeSequencing() PUBLIC: In case native sequencing is not already used, immediately switches to native sequencing.
boolean	shouldUseSeparateConnection() PUBLIC: Indicate whether separate connection(s) for sequencing could be used (by default it couldn't).
void	shouldUseTableSequencing() PUBLIC: In case table sequencing is not already used, immediately switches to table sequencing.
boolean	usesCustomSequencing() ADVANCED: Indicate whether custom sequencing is used: neither native nor table.
boolean	usesNativeSequencing() PUBLIC: Indicate whether native sequencing is used.
boolean	usesTableSequencing() PUBLIC: Indicate whether table sequencing is used

Method Detail

getValueGenerationPolicy

public SequencingValueGenerationPolicy getValueGenerationPolicy()

ADVANCED: Retun currently used sequencing value generation policy.

See Also:

SequencingValueGenerationPolicy

setValueGenerationPolicy

public void setValueGenerationPolicy(SequencingValueGenerationPolicy policy)

ADVANCED: Set sequencing value generation policy. Use this to set a custom sequencing value generation policy. If this method not called (or called with policy==null) then the default sequencing will be created: either table sequencing or native sequencing, depending on the setting in the project.

See Also:

SequencingValueGenerationPolicy

resetSequencing

public void resetSequencing()

ADVANCED: Immediately re-create sequencing object. The only reason to use this method is to pick up all parameters' values that were changed after the original sequencing object has been created.

shouldUseNativeSequencing

public void shouldUseNativeSequencing()

PUBLIC: In case native sequencing is not already used, immediately switches to native sequencing.

usesNativeSequencing

public boolean usesNativeSequencing()

PUBLIC: Indicate whether native sequencing is used.

shouldUseTableSequencing

public void shouldUseTableSequencing()

PUBLIC: In case table sequencing is not already used, immediately switches to table sequencing.

usesTableSequencing

public boolean usesTableSequencing()

PUBLIC: Indicate whether table sequencing is used

usesCustomSequencing

public boolean usesCustomSequencing()

ADVANCED: Indicate whether custom sequencing is used: neither native nor table.

shouldUseSeparateConnection

public boolean shouldUseSeparateConnection()

PUBLIC: Indicate whether separate connection(s) for sequencing could be used (by default it couldn't). If this flag is set to true then separate connection(s) for sequencing will be used in case getSequencingValueGenerationPolicy().shouldUseSeparateConnection() returns true.

See Also:

SequencingValueGenerationPolicy

setShouldUseSeparateConnection

public void setShouldUseSeparateConnection(boolean shouldUseSeparateConnection)

PUBLIC: Set whether separate connection(s) for sequencing could be used (by default it couldn't). If this flag is set to true then separate connection(s) for sequencing will be used in case getSequencingValueGenerationPolicy().shouldUseSeparateConnection() returns true.

See Also:

SequencingValueGenerationPolicy

isConnectedUsingSeparateConnection

public boolean isConnectedUsingSeparateConnection()

PUBLIC: Indicates whether sequencing actually uses separate connection(s). Returns true if sequencing is connected and uses separate connection(s). Returns false if sequencing is not connected (getSequencing()==null). Note that if shouldUseSeparateConnection() returns false this method also returns false. However if shouldUseSeparateConnection() returns true this method returns false in the following two cases: sequencing is not connected; getSequencingValueGenerationPolicy().shouldUseSeparateConnection() == false.

See Also:

SequencingValueGenerationPolicy

getLogin

public DatabaseLogin getLogin()

ADVANCED: Return a DatabaseLogin to be used by separate sequencing connection(s).

See Also:

DatabaseLogin

setLogin

public void setLogin(DatabaseLogin login)

ADVANCED: Returns a DatabaseLogin to be used by separate sequencing connection(s) The set value is ignored if shouldUseSeparateConnection() returns false. The DatabaseLogin *MUST*: 1. specify *NON-JTS* connections (such as NON_JTS driver or read-only datasource); 2. sequenceLogin.shouldUseExternalTransactionController()==false In case this method is not called, but separate connection should be used, sequencing will use a clone of login owned by the DatabaseSession, or a clone of read login owned by ServerSession.

See Also:

DatabaseLogin

getMinPoolSize

public int getMinPoolSize()

PUBLIC: Returns a minimum number of connections in sequencing connection pool.

See Also:

ConnectionPool, ServerSession

setMinPoolSize

public void setMinPoolSize(int size)

PUBLIC: Sets a minimum number of connections in sequencing connection pool The set value is ignored if shouldUseSeparateConnection() returns false. The set value is ignored if SequencingControl has been obtained not from ServerSession. By default is 2.

See Also:

ConnectionPool, ServerSession

getMaxPoolSize

public int getMaxPoolSize()

PUBLIC: Returns a maximum number of connections in sequencing connection pool

See Also:

ConnectionPool, ServerSession

setMaxPoolSize

public void setMaxPoolSize(int size)

PUBLIC: Sets a maximum number of connections in sequencing connection pool The set value is ignored if shouldUseSeparateConnection() returns false. The set value is ignored if SequencingControl has been obtained not from ServerSession. By default is 2.

See Also:

ConnectionPool, ServerSession

getPreallocationSize

public int getPreallocationSize()

PUBLIC: Returns a number of new sequencing objects to be obtained at a time.

See Also:

SequencingValueGenerationPolicy

setPreallocationSize

public void setPreallocationSize(int size)

PUBLIC: Sets a number of new sequencing objects to be obtained at a time. The set value is ignored if getSequencingValueGenarationPolicy().shouldUsePreallocation() returns false. Default value is set in the project (sequencing preallocation size).

See Also:

SequencingValueGenerationPolicy

initializePreallocated

public void initializePreallocated()

ADVANCED: Removes all preallocated sequencing objects. Ignored if getSequencingValueGenarationPolicy().shouldUsePreallocation() returns false. This method is called internally after Sequencing object is destructed.

See Also:

SequencingValueGenerationPolicy