org.eclipse.persistence.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:

Sequence, DatabaseSession

Method Summary

Login	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.
void	initializePreallocated() ADVANCED: Removes all preallocated sequencing objects.
void	initializePreallocated(java.lang.String seqName) ADVANCED: Removes all preallocated sequencing objects for the given sequence name.
boolean	isConnectedUsingSeparateConnection() PUBLIC: Indicates whether sequencing actually uses separate connection(s).
void	resetSequencing() ADVANCED: Immediately re-create sequencing object.
void	setConnectionPool(ConnectionPool pool) ADVANCED: Set the connection pool to use for sequencing.
void	setInitialPoolSize(int size) PUBLIC: Sets a initial number of connections in sequencing connection pool The set value is ignored if shouldUseSeparateConnection() returns false.
void	setLogin(Login 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	setShouldUseSeparateConnection(boolean shouldUseSeparateConnection) PUBLIC: Set whether separate connection(s) for sequencing could be used (by default it couldn't).
boolean	shouldUseSeparateConnection() PUBLIC: Indicate whether separate connection(s) for sequencing could be used (by default it couldn't).

Method Detail

resetSequencing

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.

shouldUseSeparateConnection

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 getSequence().shouldUseSeparateConnection() returns true.

See Also:

Sequence

setShouldUseSeparateConnection

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 getSequence().shouldUseSeparateConnection() returns true.

See Also:

Sequence

isConnectedUsingSeparateConnection

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;
getSequence().shouldUseSeparateConnection() == false.

See Also:

Sequence

getLogin

Login getLogin()

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

See Also:

DatabaseLogin

setLogin

void setLogin(Login 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

setConnectionPool

void setConnectionPool(ConnectionPool pool)

ADVANCED: Set the connection pool to use for sequencing.

getMinPoolSize

int getMinPoolSize()

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

See Also:

ConnectionPool, ServerSession

setMinPoolSize

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

int getMaxPoolSize()

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

See Also:

ConnectionPool, ServerSession

setMaxPoolSize

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

setInitialPoolSize

void setInitialPoolSize(int size)

PUBLIC: Sets a initial 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 1.

See Also:

ConnectionPool, ServerSession

initializePreallocated

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:

Sequence

initializePreallocated

void initializePreallocated(java.lang.String seqName)

ADVANCED: Removes all preallocated sequencing objects for the given sequence name. Ignored if getSequencingValueGenarationPolicy().shouldUsePreallocation() returns false.

See Also:

Sequence