org.h2.engine
Class Session

java.lang.Object
  org.h2.engine.SessionWithState
      org.h2.engine.Session

All Implemented Interfaces:

SessionInterface

public class Session
extends SessionWithState

A session represents an embedded database connection. When using the server mode, this object resides on the server side and communicates with a SessionRemote object on the client side.

Field Summary

Fields inherited from class org.h2.engine.SessionWithState

sessionState, sessionStateChanged

Constructor Summary

Session(Database database, User user, int id)

Method Summary

void	addLocalTempTable(Table table) Add a local temporary table to this session.
void	addLocalTempTableConstraint(Constraint constraint) Add a local temporary constraint to this session.
void	addLocalTempTableIndex(Index index) Add a local temporary index to this session.
void	addLock(Table table) Add a lock for the given table.
void	addLogPos(int logId, int pos) Called when a log entry for this session is added.
void	addProcedure(Procedure procedure) Add a procedure to this session.
void	addSavepoint(java.lang.String name) Create a savepoint that is linked to the current log position.
void	addTemporaryResult(ResultInterface result) Remember the result set and close it as soon as the transaction is committed (if it needs to be closed).
void	afterWriting() Called after writing has ended.
void	begin() Begin a transaction.
void	cancel() Cancel the current or next command (called when closing a connection).
void	checkCanceled() Check if the current transaction is canceled by calling Statement.cancel() or because a session timeout was set and expired.
void	close() Roll back pending transactions and close the session.
void	closeTemporaryResults() Close all temporary result set.
void	commit(boolean ddl) Commit the current transaction.
JdbcConnection	createConnection(boolean columnList) Create an internal connection.
protected void	finalize()
Table	findLocalTempTable(java.lang.String name) Get the local temporary table if one exists with that name, or null if not.
Constraint	findLocalTempTableConstraint(java.lang.String name) Get the local temporary constraint if one exists with that name, or null if not.
Index	findLocalTempTableIndex(java.lang.String name) Get the local temporary index if one exists with that name, or null if not.
boolean	getAllowLiterals()
boolean	getAutoCommit()
Command	getCurrentCommand()
long	getCurrentCommandStart()
java.lang.String	getCurrentSchemaName()
Database	getDatabase()
DataHandler	getDataHandler() Get the data handler object.
int	getFirstUncommittedLog()
int	getFirstUncommittedPos()
int	getId()
Value	getLastIdentity()
int	getLastUncommittedDelete()
java.util.HashMap<java.lang.String,Constraint>	getLocalTempTableConstraints() Get the map of constraints for all constraints on local, temporary tables, if any.
java.util.HashMap<java.lang.String,Index>	getLocalTempTableIndexes()
ObjectArray<Table>	getLocalTempTables()
Table[]	getLocks()
int	getLockTimeout()
int	getLogId()
int	getModificationId()
java.lang.String	getNextSystemIdentifier(java.lang.String sql) Get the next system generated identifiers.
int	getPowerOffCount() Get the number of disk operations before power failure is simulated.
Procedure	getProcedure(java.lang.String name) Get the procedure with the given name, or null if none exists.
int	getQueryTimeout()
java.util.Random	getRandom()
java.lang.String[]	getSchemaSearchPath()
Value	getScopeIdentity()
long	getSessionStart()
Trace	getTrace() Get the trace object
Value	getTransactionId()
User	getUser()
Value	getVariable(java.lang.String name) Get the value of the specified user defined variable.
java.lang.String[]	getVariableNames() Get the list of variable names that are set for this session.
Table	getWaitForLock()
int	hashCode()
boolean	isClosed() Check if close was called.
boolean	isReconnectNeeded(boolean write) Check if the database changed and therefore reconnecting is required.
boolean	isRedoLogBinaryEnabled()
boolean	isUndoLogEnabled()
void	log(Table table, short type, Row row) Add an undo log entry to this session.
int	nextObjectId() Get the next object id.
Prepared	prepare(java.lang.String sql) Parse and prepare the given SQL statement.
Prepared	prepare(java.lang.String sql, boolean rightsChecked) Parse and prepare the given SQL statement.
CommandInterface	prepareCommand(java.lang.String sql, int fetchSize) Parse a command and prepare it for execution.
void	prepareCommit(java.lang.String transactionName) Prepare the given transaction.
Command	prepareLocal(java.lang.String sql) Parse and prepare the given SQL statement.
SessionInterface	reconnect(boolean write) Close the connection and open a new connection.
void	removeLocalTempTable(Table table) Drop and remove the given local temporary table from this session.
void	removeLocalTempTableConstraint(Constraint constraint) Drop and remove the given local temporary constraint from this session.
void	removeLocalTempTableIndex(Index index) Drop and remove the given local temporary index from this session.
void	removeProcedure(java.lang.String name) Remove a procedure from this session.
void	rollback() Fully roll back the current transaction.
void	rollbackTo(int index, boolean trimToSize) Partially roll back the current transaction.
void	rollbackToSavepoint(java.lang.String name) Undo all operations back to the log position of the given savepoint.
void	setAllCommitted() This method is called after the log file has committed this session.
void	setAllowLiterals(boolean b)
void	setAutoCommit(boolean b) Change the autocommit setting for this session.
boolean	setCommitOrRollbackDisabled(boolean x)
void	setConnectionInfo(ConnectionInfo ci)
void	setCurrentCommand(Command command, long startTime) Set the current command of this session.
void	setCurrentSchema(Schema schema)
void	setLastIdentity(Value last)
void	setLastUncommittedDelete(int deleteId)
void	setLockTimeout(int lockTimeout)
void	setPowerOffCount(int count) Set the number of disk operations before power failure is simulated.
void	setPreparedTransaction(java.lang.String transactionName, boolean commit) Commit or roll back the given transaction.
void	setQueryTimeout(int queryTimeout)
void	setRedoLogBinary(boolean b)
void	setSchemaSearchPath(java.lang.String[] schemas)
void	setScopeIdentity(Value scopeIdentity)
void	setThrottle(int throttle)
void	setUndoLogEnabled(boolean b)
void	setVariable(java.lang.String name, Value value) Set the value of the given variable for this session.
void	setWaitForLock(Table table)
void	throttle() Wait for some time if this session is throttled (slowed down).
java.lang.String	toString()
void	unlinkAtCommit(ValueLob v) Remember that the given LOB value must be un-linked (disconnected from the table) at commit.
void	unlinkAtCommitStop(Value v) Do not unlink this LOB value at commit any longer.
void	unlockReadLocks() Unlock all read locks.
void	waitIfExclusiveModeEnabled() Wait if the exclusive mode has been enabled for another session.

Methods inherited from class org.h2.engine.SessionWithState

readSessionState, recreateSessionState

Methods inherited from class java.lang.Object

clone, equals, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

Session

public Session(Database database,
               User user,
               int id)

Method Detail

setCommitOrRollbackDisabled

public boolean setCommitOrRollbackDisabled(boolean x)

setVariable

public void setVariable(java.lang.String name,
                        Value value)
                 throws java.sql.SQLException

Set the value of the given variable for this session.

Parameters:

name - the name of the variable (may not be null)

value - the new value (may not be null)

Throws:

java.sql.SQLException

getVariable

public Value getVariable(java.lang.String name)

Get the value of the specified user defined variable. This method always returns a value; it returns ValueNull.INSTANCE if the variable doesn't exist.

Parameters:

name - the variable name

Returns:

the value, or NULL

getVariableNames

public java.lang.String[] getVariableNames()

Get the list of variable names that are set for this session.

Returns:

the list of names

findLocalTempTable

public Table findLocalTempTable(java.lang.String name)

Get the local temporary table if one exists with that name, or null if not.

Parameters:

name - the table name

Returns:

the table, or null

getLocalTempTables

public ObjectArray<Table> getLocalTempTables()

addLocalTempTable

public void addLocalTempTable(Table table)
                       throws java.sql.SQLException

Add a local temporary table to this session.

Parameters:

table - the table to add

Throws:

java.sql.SQLException - if a table with this name already exists

removeLocalTempTable

public void removeLocalTempTable(Table table)
                          throws java.sql.SQLException

Drop and remove the given local temporary table from this session.

Parameters:

table - the table

Throws:

java.sql.SQLException

findLocalTempTableIndex

public Index findLocalTempTableIndex(java.lang.String name)

Get the local temporary index if one exists with that name, or null if not.

Parameters:

name - the table name

Returns:

the table, or null

getLocalTempTableIndexes

public java.util.HashMap<java.lang.String,Index> getLocalTempTableIndexes()

addLocalTempTableIndex

public void addLocalTempTableIndex(Index index)
                            throws java.sql.SQLException

Add a local temporary index to this session.

Parameters:

index - the index to add

Throws:

java.sql.SQLException - if a index with this name already exists

removeLocalTempTableIndex

public void removeLocalTempTableIndex(Index index)
                               throws java.sql.SQLException

Drop and remove the given local temporary index from this session.

Parameters:

index - the index

Throws:

java.sql.SQLException

findLocalTempTableConstraint

public Constraint findLocalTempTableConstraint(java.lang.String name)

Get the local temporary constraint if one exists with that name, or null if not.

Parameters:

name - the constraint name

Returns:

the constraint, or null

getLocalTempTableConstraints

public java.util.HashMap<java.lang.String,Constraint> getLocalTempTableConstraints()

Get the map of constraints for all constraints on local, temporary tables, if any. The map's keys are the constraints' names.

Returns:

the map of constraints, or null

addLocalTempTableConstraint

public void addLocalTempTableConstraint(Constraint constraint)
                                 throws java.sql.SQLException

Add a local temporary constraint to this session.

Parameters:

constraint - the constraint to add

Throws:

java.sql.SQLException - if a constraint with the same name already exists

removeLocalTempTableConstraint

public void removeLocalTempTableConstraint(Constraint constraint)
                                    throws java.sql.SQLException

Drop and remove the given local temporary constraint from this session.

Parameters:

constraint - the constraint

Throws:

java.sql.SQLException

finalize

protected void finalize()

Overrides:

finalize in class java.lang.Object

getAutoCommit

public boolean getAutoCommit()

getUser

public User getUser()

setAutoCommit

public void setAutoCommit(boolean b)

Change the autocommit setting for this session.

Parameters:

b - the new value

getLockTimeout

public int getLockTimeout()

setLockTimeout

public void setLockTimeout(int lockTimeout)

prepareCommand

public CommandInterface prepareCommand(java.lang.String sql,
                                       int fetchSize)
                                throws java.sql.SQLException

Description copied from interface: SessionInterface

Parse a command and prepare it for execution.

Parameters:

sql - the SQL statement

fetchSize - the number of rows to fetch in one step

Returns:

the prepared command

Throws:

java.sql.SQLException

prepare

public Prepared prepare(java.lang.String sql)
                 throws java.sql.SQLException

Parse and prepare the given SQL statement. This method also checks the rights.

Parameters:

sql - the SQL statement

Returns:

the prepared statement

Throws:

java.sql.SQLException

prepare

public Prepared prepare(java.lang.String sql,
                        boolean rightsChecked)
                 throws java.sql.SQLException

Parse and prepare the given SQL statement.

Parameters:

sql - the SQL statement

rightsChecked - true if the rights have already been checked

Returns:

the prepared statement

Throws:

java.sql.SQLException

prepareLocal

public Command prepareLocal(java.lang.String sql)
                     throws java.sql.SQLException

Parse and prepare the given SQL statement. This method also checks if the connection has been closed.

Parameters:

sql - the SQL statement

Returns:

the prepared statement

Throws:

java.sql.SQLException

getDatabase

public Database getDatabase()

getPowerOffCount

public int getPowerOffCount()

Description copied from interface: SessionInterface

Get the number of disk operations before power failure is simulated. This is used for testing. If not set, 0 is returned

Returns:

the number of operations, or 0

setPowerOffCount

public void setPowerOffCount(int count)

Description copied from interface: SessionInterface

Set the number of disk operations before power failure is simulated. To disable the countdown, use 0.

Parameters:

count - the number of operations

getLastUncommittedDelete

public int getLastUncommittedDelete()

setLastUncommittedDelete

public void setLastUncommittedDelete(int deleteId)

commit

public void commit(boolean ddl)
            throws java.sql.SQLException

Commit the current transaction. If the statement was not a data definition statement, and if there are temporary tables that should be dropped or truncated at commit, this is done as well.

Parameters:

ddl - if the statement was a data definition statement

Throws:

java.sql.SQLException

rollback

public void rollback()
              throws java.sql.SQLException

Fully roll back the current transaction.

Throws:

java.sql.SQLException

rollbackTo

public void rollbackTo(int index,
                       boolean trimToSize)
                throws java.sql.SQLException

Partially roll back the current transaction.

Parameters:

index - the position to which should be rolled back

trimToSize - if the list should be trimmed

Throws:

java.sql.SQLException

getLogId

public int getLogId()

getId

public int getId()

cancel

public void cancel()

Description copied from interface: SessionInterface

Cancel the current or next command (called when closing a connection).

close

public void close()
           throws java.sql.SQLException

Description copied from interface: SessionInterface

Roll back pending transactions and close the session.

Throws:

java.sql.SQLException

addLock

public void addLock(Table table)

Add a lock for the given table. The object is unlocked on commit or rollback.

Parameters:

table - the table that is locked

log

public void log(Table table,
                short type,
                Row row)
         throws java.sql.SQLException

Add an undo log entry to this session.

Parameters:

table - the table

type - the operation type (see UndoLogRecord)

row - the row

Throws:

java.sql.SQLException

unlockReadLocks

public void unlockReadLocks()

Unlock all read locks. This is done if the transaction isolation mode is READ_COMMITTED.

getRandom

public java.util.Random getRandom()

getTrace

public Trace getTrace()

Description copied from interface: SessionInterface

Get the trace object

Returns:

the trace object

setLastIdentity

public void setLastIdentity(Value last)

getLastIdentity

public Value getLastIdentity()

addLogPos

public void addLogPos(int logId,
                      int pos)

Called when a log entry for this session is added. The session keeps track of the first entry in the log file that is not yet committed.

Parameters:

logId - the log file id

pos - the position of the log entry in the log file

getFirstUncommittedLog

public int getFirstUncommittedLog()

getFirstUncommittedPos

public int getFirstUncommittedPos()

setAllCommitted

public void setAllCommitted()

This method is called after the log file has committed this session.

addSavepoint

public void addSavepoint(java.lang.String name)

Create a savepoint that is linked to the current log position.

Parameters:

name - the savepoint name

rollbackToSavepoint

public void rollbackToSavepoint(java.lang.String name)
                         throws java.sql.SQLException

Undo all operations back to the log position of the given savepoint.

Parameters:

name - the savepoint name

Throws:

java.sql.SQLException

prepareCommit

public void prepareCommit(java.lang.String transactionName)
                   throws java.sql.SQLException

Prepare the given transaction.

Parameters:

transactionName - the name of the transaction

Throws:

java.sql.SQLException

setPreparedTransaction

public void setPreparedTransaction(java.lang.String transactionName,
                                   boolean commit)
                            throws java.sql.SQLException

Commit or roll back the given transaction.

Parameters:

transactionName - the name of the transaction

commit - true for commit, false for rollback

Throws:

java.sql.SQLException

isClosed

public boolean isClosed()

Description copied from interface: SessionInterface

Check if close was called.

Returns:

if the session has been closed

setThrottle

public void setThrottle(int throttle)

throttle

public void throttle()

Wait for some time if this session is throttled (slowed down).

setCurrentCommand

public void setCurrentCommand(Command command,
                              long startTime)

Set the current command of this session. This is done just before executing the statement.

Parameters:

command - the command

startTime - the time execution has been started

checkCanceled

public void checkCanceled()
                   throws java.sql.SQLException

Check if the current transaction is canceled by calling Statement.cancel() or because a session timeout was set and expired.

Throws:

java.sql.SQLException - if the transaction is canceled

getCurrentCommand

public Command getCurrentCommand()

getCurrentCommandStart

public long getCurrentCommandStart()

getAllowLiterals

public boolean getAllowLiterals()

setAllowLiterals

public void setAllowLiterals(boolean b)

setCurrentSchema

public void setCurrentSchema(Schema schema)

getCurrentSchemaName

public java.lang.String getCurrentSchemaName()

createConnection

public JdbcConnection createConnection(boolean columnList)

Create an internal connection. This connection is used when initializing triggers, and when calling user defined functions.

Parameters:

columnList - if the url should be 'jdbc:columnlist:connection'

Returns:

the internal connection

getDataHandler

public DataHandler getDataHandler()

Description copied from interface: SessionInterface

Get the data handler object.

Returns:

the data handler

unlinkAtCommit

public void unlinkAtCommit(ValueLob v)

Remember that the given LOB value must be un-linked (disconnected from the table) at commit.

Parameters:

v - the value

unlinkAtCommitStop

public void unlinkAtCommitStop(Value v)

Do not unlink this LOB value at commit any longer.

Parameters:

v - the value

getNextSystemIdentifier

public java.lang.String getNextSystemIdentifier(java.lang.String sql)

Get the next system generated identifiers. The identifier returned does not occur within the given SQL statement.

Parameters:

sql - the SQL statement

Returns:

the new identifier

addProcedure

public void addProcedure(Procedure procedure)

Add a procedure to this session.

Parameters:

procedure - the procedure to add

removeProcedure

public void removeProcedure(java.lang.String name)

Remove a procedure from this session.

Parameters:

name - the name of the procedure to remove

getProcedure

public Procedure getProcedure(java.lang.String name)

Get the procedure with the given name, or null if none exists.

Parameters:

name - the procedure name

Returns:

the procedure or null

setSchemaSearchPath

public void setSchemaSearchPath(java.lang.String[] schemas)

getSchemaSearchPath

public java.lang.String[] getSchemaSearchPath()

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

setUndoLogEnabled

public void setUndoLogEnabled(boolean b)

setRedoLogBinary

public void setRedoLogBinary(boolean b)

isUndoLogEnabled

public boolean isUndoLogEnabled()

begin

public void begin()

Begin a transaction.

getSessionStart

public long getSessionStart()

getLocks

public Table[] getLocks()

waitIfExclusiveModeEnabled

public void waitIfExclusiveModeEnabled()

Wait if the exclusive mode has been enabled for another session. This method returns as soon as the exclusive mode has been disabled.

addTemporaryResult

public void addTemporaryResult(ResultInterface result)

Remember the result set and close it as soon as the transaction is committed (if it needs to be closed). This is done to delete temporary files as soon as possible, and free object ids of temporary tables.

Parameters:

result - the temporary result set

closeTemporaryResults

public void closeTemporaryResults()

Close all temporary result set. This also deletes all temporary files held by the result sets.

setQueryTimeout

public void setQueryTimeout(int queryTimeout)

getQueryTimeout

public int getQueryTimeout()

setWaitForLock

public void setWaitForLock(Table table)

getWaitForLock

public Table getWaitForLock()

getModificationId

public int getModificationId()

isReconnectNeeded

public boolean isReconnectNeeded(boolean write)

Description copied from interface: SessionInterface

Check if the database changed and therefore reconnecting is required.

Parameters:

write - if the next operation may be writing

Returns:

true if reconnecting is required

afterWriting

public void afterWriting()

Description copied from interface: SessionInterface

Called after writing has ended. It needs to be called after isReconnectNeeded(true) returned false.

reconnect

public SessionInterface reconnect(boolean write)
                           throws java.sql.SQLException

Description copied from interface: SessionInterface

Close the connection and open a new connection.

Parameters:

write - if the next operation may be writing

Returns:

the new connection

Throws:

java.sql.SQLException

setConnectionInfo

public void setConnectionInfo(ConnectionInfo ci)

getTransactionId

public Value getTransactionId()

nextObjectId

public int nextObjectId()

Get the next object id.

Returns:

the next object id

setScopeIdentity

public void setScopeIdentity(Value scopeIdentity)

getScopeIdentity

public Value getScopeIdentity()

isRedoLogBinaryEnabled

public boolean isRedoLogBinaryEnabled()