org.apache.derby.iapi.sql
Interface Activation

All Superinterfaces:
Dependable, Dependent
All Known Subinterfaces:
CursorActivation
All Known Implementing Classes:
BaseActivation, ConstantActionActivation, CursorActivation, GenericActivationHolder

public interface Activation
extends Dependent

An activation contains all the local state information necessary to execute a re-entrant PreparedStatement. The way it will actually work is that a PreparedStatement will have an executable plan, which will be a generated class. All of the local state will be variables in the class. Creating a new instance of the executable plan will create the local state variables. This means that an executable plan must implement this interface, and that the PreparedStatement.getActivation() method will do a "new" operation on the executable plan.

The fixed implementations of Activation in the Execution impl package are used as skeletons for the classes generated for statements when they are compiled.

There are no fixed implementations of Activation for statements; a statement has an activation generated for it when it is compiled.


Field Summary
 
Fields inherited from interface org.apache.derby.catalog.Dependable
ACTIVATION, ALIAS, COLUMNS_IN_TABLE, COLUMNS_PERMISSION, CONGLOMERATE, CONSTRAINT, DEFAULT, FILE, HEAP, INDEX, PERM, PREPARED_STATEMENT, ROLE_GRANT, ROUTINE_PERMISSION, SCHEMA, SEQUENCE, STORED_PREPARED_STATEMENT, TABLE, TABLE_PERMISSION, TRIGGER, VIEW
 
Method Summary
 void addWarning(java.sql.SQLWarning w)
          Add a warning to the activation
 boolean checkIfThisActivationHasHoldCursor(java.lang.String tableName)
          Temporary tables can be declared with ON COMMIT DELETE ROWS.
 void checkStatementValidity()
          Check the validity of the current executing statement.
 void clearCurrentRow(int resultSetNumber)
          Generated plans have a current row field for ease in defining the methods and finding them dynamically.
 void clearHeapConglomerateController()
          Clear the ConglomerateController to be used for an update or delete.
 void clearIndexScanInfo()
          Clear the info for the index to be re-used for update/delete.
 void clearParentResultSets()
           
 void clearWarnings()
          Clear the activation's warnings.
 void close()
          Closing an activation statement marks it as unusable.
 ResultSet execute()
          When the prepared statement is executed, it passes execution on to the activation execution was requested for.
 int[] getAutoGeneratedKeysColumnIndexes()
          Returns the column positions array of columns requested in auto-generated keys resultset for this avtivation.
 java.lang.String[] getAutoGeneratedKeysColumnNames()
          Returns the column names array of columns requested in auto-generated keys resultset for this avtivation.
 boolean getAutoGeneratedKeysResultsetMode()
          Returns true if auto-generated keys resultset request was made for this avtivation.
 ConstantAction getConstantAction()
           
 Row getCurrentRow(int resultSetNumber)
          Get the current row at the given index.
 java.lang.String getCursorName()
          Return the cursor name of this activation.
 DataValueFactory getDataValueFactory()
          Get the DataValueFactory
 TableDescriptor getDDLTableDescriptor()
          Get the TableDescriptor for the target of DDL.
 java.sql.ResultSet[][] getDynamicResults()
          Return the set of dynamical created result sets, for procedures.
 ExecutionFactory getExecutionFactory()
          Get the ExecutionFactory
 boolean getForCreateTable()
          Get whether or not this activation is for create table.
 CursorResultSet getForUpdateIndexScan()
           
 ConglomerateController getHeapConglomerateController()
          Get the ConglomerateController, if any, that has already been opened for the heap when scaning for an update or delete.
 long getIndexConglomerateNumber()
          Get the conglomerate number of the index, if any, that has already been opened for scaning for an update or delete.
 ScanController getIndexScanController()
          Get the ScanController, if any, that has already been opened for the index when scaning for an update or delete.
 LanguageConnectionContext getLanguageConnectionContext()
          Get the language connection context associated with this activation
 int getMaxDynamicResults()
          Return the maximum number of dynamical created result sets from the procedure definition.
 int getMaxRows()
          Get the maximum # of rows. (# of rows that can be returned by a ResultSet. 0 means no limit.)
 int getNumSubqueries()
          Get the number of subqueries in the entire query.
 ParameterValueSet getParameterValueSet()
          Gets the ParameterValueSet for this execution of the statement.
 Activation getParentActivation()
          This activation is created in a dynamic call context, or substatement execution context; get its caller's or superstatement's activation.
 java.util.Vector getParentResultSet(java.lang.String resultSetId)
          get the reference to parent table ResultSets, that will be needed by the referential action dependent table scans.
 java.util.Hashtable getParentResultSets()
           
 ExecPreparedStatement getPreparedStatement()
          Get the prepared statement that this activation is for.
 ResultDescription getResultDescription()
          Get the result description for this activation, if it has one.
 ResultSet getResultSet()
          Returns the current result set for this activation, i.e.
 boolean getResultSetHoldability()
          Return the holdability of this activation.
 RowLocation getRowLocationTemplate(int itemNumber)
          Get the saved RowLocation.
 SQLSessionContext getSQLSessionContextForChildren()
          Get the current SQL session context if in a nested connection of a stored routine or in a substatement.
 java.sql.ResultSet getTargetVTI()
          Get the ResultSet for the target of an update/delete to a VTI.
 TransactionController getTransactionController()
          Get the Execution TransactionController associated with this activation/lcc.
 java.sql.SQLWarning getWarnings()
          Returns the chained list of warnings.
 void informOfRowCount(NoPutResultSet resultSet, long rowCount)
          Tell this activation that the given ResultSet was found to have the given number of rows.
 boolean isClosed()
          Find out if the activation is closed or not.
 boolean isCursorActivation()
          Is this Activation for a cursor?
 boolean isInUse()
          Is the activation in use?
 boolean isSingleExecution()
          Returns true if this Activation is only going to be used for one execution.
 void markUnused()
          Mark the activation as unused.
 void reset()
          Resets the activation to the "pre-execution" state - that is, the state where it can be used to begin a new execution.
 void setAutoGeneratedKeysResultsetInfo(int[] columnIndexes, java.lang.String[] columnNames)
          Set the auto-generated keys resultset mode to true for this activation.
 void setCurrentRow(ExecRow currentRow, int resultSetNumber)
          Generated plans have a current row field for ease in defining the methods and finding them dynamically.
 void setCursorName(java.lang.String cursorName)
          JDBC requires that all select statements be converted into cursors, and that the cursor name be settable for each execution of a select statement.
 void setDDLTableDescriptor(TableDescriptor td)
          Save the TableDescriptor for the target of DDL so that it can be passed between the various ConstantActions during execution.
 void setForCreateTable()
          Mark the Activation as being for create table.
 void setForUpdateIndexScan(CursorResultSet forUpdateResultSet)
          beetle 3865: updateable cursor using index.
 void setHeapConglomerateController(ConglomerateController updateHeapCC)
          Set the ConglomerateController to be used for an update or delete.
 void setIndexConglomerateNumber(long indexConglomerateNumber)
          Set the conglomerate number of the index to be used for an update or delete, when scanning an index that will also be updated (Saves opening the ScanController twice.)
 void setIndexScanController(ScanController indexSC)
          Set the ScanController to be used for an update or delete, when scanning an index that will also be updated (Saves opening the ScanController twice.)
 void setMaxRows(int maxRows)
          Set the maximum # of rows. (# of rows that can be returned by a ResultSet. 0 means no limit.)
 void setParameters(ParameterValueSet parameterValues, DataTypeDescriptor[] parameterTypes)
          Sets the parameter values for this execution of the statement.
 void setParentActivation(Activation a)
          This activation is created in a dynamic call context or a substatement execution context, chain its parent statements activation..
 void setParentResultSet(TemporaryRowHolder rs, java.lang.String resultSetId)
           
 void setResultSetHoldability(boolean resultSetHoldability)
          Set current resultset holdability.
 void setSingleExecution()
          Set this Activation for a single execution.
 void setTargetVTI(java.sql.ResultSet targetVTI)
          Save the ResultSet for the target of an update/delete to a VTI.
 SQLSessionContext setupSQLSessionContextForChildren(boolean push)
          Set up and return the current SQL session context for all immediately nested connections stemming from the call or function invocation of the statement corresponding to this activation (push=true) or for a substatement, which shares the parents statement's session context (push=false).
 
Methods inherited from interface org.apache.derby.iapi.sql.depend.Dependent
isValid, makeInvalid, prepareToInvalidate
 
Methods inherited from interface org.apache.derby.catalog.Dependable
getClassType, getDependableFinder, getObjectID, getObjectName, isPersistent
 

Method Detail

reset

void reset()
           throws StandardException
Resets the activation to the "pre-execution" state - that is, the state where it can be used to begin a new execution. Frees local buffers, stops scans, resets counters to zero, sets current date and time to an unitialized state, etc.

Throws:
StandardException - thrown on failure

setCursorName

void setCursorName(java.lang.String cursorName)
JDBC requires that all select statements be converted into cursors, and that the cursor name be settable for each execution of a select statement. The Language Module will support this, so that the JDBC driver will not have to parse JSQL text. This method will have no effect when called on non-select statements.

There will be a JSQL statement to disable the "cursorization" of all select statements. For non-cursorized select statements, this method will have no effect.

This has no effect if the activation has been closed.

Parameters:
cursorName - The cursor name to use.

checkIfThisActivationHasHoldCursor

boolean checkIfThisActivationHasHoldCursor(java.lang.String tableName)
Temporary tables can be declared with ON COMMIT DELETE ROWS. But if the table has a held curosr open at commit time, data should not be deleted from the table. This method, (gets called at commit time) checks if this activation held cursor and if so, does that cursor reference the passed temp table name.

Returns:
true if this activation has held cursor and if it references the passed temp table name

getParameterValueSet

ParameterValueSet getParameterValueSet()
Gets the ParameterValueSet for this execution of the statement.

Returns:
The ParameterValueSet for this execution of the statement. Returns NULL if there are no parameters.

setParameters

void setParameters(ParameterValueSet parameterValues,
                   DataTypeDescriptor[] parameterTypes)
                   throws StandardException
Sets the parameter values for this execution of the statement.

Has no effect if the activation has been closed.

NOTE: The setParameters() method is currently unimplemented. A statement with parameters will generate its own ParameterValueSet, which can be gotten with the getParameterValueSet() method (above). The idea behind setParameters() is to improve performance when operating across a network by allowing all the parameters to be set in one call, as opposed to one call per parameter.

Parameters:
parameterValues - The values of the parameters.
Throws:
StandardException

execute

ResultSet execute()
                  throws StandardException
When the prepared statement is executed, it passes execution on to the activation execution was requested for.

Returns:
the ResultSet for further manipulation, if any.
Throws:
StandardException - Thrown on failure

close

void close()
           throws StandardException
Closing an activation statement marks it as unusable. Any other requests made on it will fail. An activation should be marked closed when it is expected to not be used any longer, i.e. when the connection for it is closed, or it has suffered some sort of severe error. This will also close its result set and release any resources it holds e.g. for parameters.

Any class that implements this must be prepared to be executed from garbage collection, ie. there is no matching context stack.

Throws:
StandardException - Thrown on failure

isClosed

boolean isClosed()
Find out if the activation is closed or not.

Returns:
true if the Activation has been closed.

setSingleExecution

void setSingleExecution()
Set this Activation for a single execution. E.g. a java.sql.Statement execution.


isSingleExecution

boolean isSingleExecution()
Returns true if this Activation is only going to be used for one execution.


getWarnings

java.sql.SQLWarning getWarnings()
Returns the chained list of warnings. Returns null if there are no warnings.


addWarning

void addWarning(java.sql.SQLWarning w)
Add a warning to the activation


clearWarnings

void clearWarnings()
Clear the activation's warnings.


getLanguageConnectionContext

LanguageConnectionContext getLanguageConnectionContext()
Get the language connection context associated with this activation


getTransactionController

TransactionController getTransactionController()
Get the Execution TransactionController associated with this activation/lcc.


getResultSet

ResultSet getResultSet()
Returns the current result set for this activation, i.e. the one returned by the last execute() call. If there has been no execute call or the activation has been reset or closed, a null is returned.

Returns:
the current ResultSet of this activation.

setCurrentRow

void setCurrentRow(ExecRow currentRow,
                   int resultSetNumber)
Generated plans have a current row field for ease in defining the methods and finding them dynamically. The interface is used to set the row before a dynamic method that uses it is invoked.

When all processing on the currentRow has been completed, callers should call activation.clearCurrentRow(resultSetNumber) to ensure that no unnecessary references are retained to rows. This will allow the rows no longer in use to be collected by the garbage collecter.

Parameters:
currentRow - The row to be operated upon.
resultSetNumber - The resultSetNumber for the current ResultSet

getCurrentRow

Row getCurrentRow(int resultSetNumber)
Get the current row at the given index.


clearCurrentRow

void clearCurrentRow(int resultSetNumber)
Generated plans have a current row field for ease in defining the methods and finding them dynamically. The interface is used to set the row before a dynamic method that uses it is invoked.

When all processing on the currentRow has been completed, callers should call activation.clearCurrentRow(resultSetNumber) to ensure that no unnecessary references are retained to rows. This will allow the rows no longer in use to be collected by the garbage collecter.

Parameters:
resultSetNumber - The resultSetNumber for the current ResultSet

getPreparedStatement

ExecPreparedStatement getPreparedStatement()
Get the prepared statement that this activation is for.

Returns:
the prepared statement this activation is for.

checkStatementValidity

void checkStatementValidity()
                            throws StandardException
Check the validity of the current executing statement. Needs to be called after a statement has obtained the relevant table locks on the

Throws:
StandardException

getResultDescription

ResultDescription getResultDescription()
Get the result description for this activation, if it has one.

Returns:
result description for this activation, if it has one; otherwise, null.

getDataValueFactory

DataValueFactory getDataValueFactory()
Get the DataValueFactory

Returns:
DataValueFactory

getExecutionFactory

ExecutionFactory getExecutionFactory()
Get the ExecutionFactory

Returns:
ExecutionFactory

getRowLocationTemplate

RowLocation getRowLocationTemplate(int itemNumber)
Get the saved RowLocation.

Parameters:
itemNumber - The saved item number.
Returns:
A RowLocation template for the conglomerate

getNumSubqueries

int getNumSubqueries()
Get the number of subqueries in the entire query.

Returns:
int The number of subqueries in the entire query.

getCursorName

java.lang.String getCursorName()
Return the cursor name of this activation. This will differ from its ResultSet's cursor name if it has been altered with setCursorName. Thus this always returns the cursor name of the next execution of this activation. The cursor name of the current execution must be obtained from the ResultSet. or this.getResultSet.getCursorName() [with null checking].

Statements that do not support cursors will return a null.

Returns:
The cursor name.

getResultSetHoldability

boolean getResultSetHoldability()
Return the holdability of this activation.

Returns:
The holdability of this activation.

setResultSetHoldability

void setResultSetHoldability(boolean resultSetHoldability)
Set current resultset holdability.

Parameters:
resultSetHoldability - The new resultset holdability.

setAutoGeneratedKeysResultsetInfo

void setAutoGeneratedKeysResultsetInfo(int[] columnIndexes,
                                       java.lang.String[] columnNames)
Set the auto-generated keys resultset mode to true for this activation. The specific columns for auto-generated keys resultset can be requested by passing column positions array The specific columns for auto-generated keys resultset can be requested by passing column names array Both the parameters would be null if user didn't request specific keys. Otherwise, the user could request specific columns by passing column positions or names array but not both.

Parameters:
columnIndexes - Request specific columns in auto-generated keys resultset by passing column positions. null means no specific columns requested by position
columnNames - Request specific columns in auto-generated keys resultset by passing column names. null means no specific columns requested by position

getAutoGeneratedKeysResultsetMode

boolean getAutoGeneratedKeysResultsetMode()
Returns true if auto-generated keys resultset request was made for this avtivation.

Returns:
auto-generated keys resultset mode for this activation.

getAutoGeneratedKeysColumnIndexes

int[] getAutoGeneratedKeysColumnIndexes()
Returns the column positions array of columns requested in auto-generated keys resultset for this avtivation. Returns null if no specific column requested by positions

Returns:
column positions array of columns requested.

getAutoGeneratedKeysColumnNames

java.lang.String[] getAutoGeneratedKeysColumnNames()
Returns the column names array of columns requested in auto-generated keys resultset for this avtivation. Returns null if no specific column requested by names

Returns:
column names array of columns requested.

markUnused

void markUnused()
Mark the activation as unused.


isInUse

boolean isInUse()
Is the activation in use?

Returns:
true/false

informOfRowCount

void informOfRowCount(NoPutResultSet resultSet,
                      long rowCount)
                      throws StandardException
Tell this activation that the given ResultSet was found to have the given number of rows. This is used during execution to determine whether a table has grown or shrunk. If a table's size changes significantly, the activation may invalidate its PreparedStatement to force recompilation. Note that the association of row counts with ResultSets is kept in the activation class, not in the activation itself. This means that this method must be synchronized. This method is not required to check the number of rows on each call. Because of synchronization, this check is likely to be expensive, so it may only check every hundred calls or so.

Throws:
StandardException - Thrown on error

getHeapConglomerateController

ConglomerateController getHeapConglomerateController()
Get the ConglomerateController, if any, that has already been opened for the heap when scaning for an update or delete. (Saves opening the ConglomerateController twice.)

Returns:
The ConglomerateController, if available, to use for the update.

setHeapConglomerateController

void setHeapConglomerateController(ConglomerateController updateHeapCC)
Set the ConglomerateController to be used for an update or delete. (Saves opening the ConglomerateController twice.)

Parameters:
updateHeapCC - The ConglomerateController to reuse for the update or delete.

clearHeapConglomerateController

void clearHeapConglomerateController()
Clear the ConglomerateController to be used for an update or delete. (Saves opening the ConglomerateController twice.)


getIndexScanController

ScanController getIndexScanController()
Get the ScanController, if any, that has already been opened for the index when scaning for an update or delete. (Saves opening the ScanController twice.)

Returns:
The ScanController, if available, to use for the update.

setIndexScanController

void setIndexScanController(ScanController indexSC)
Set the ScanController to be used for an update or delete, when scanning an index that will also be updated (Saves opening the ScanController twice.)

Parameters:
indexSC - The ScanController to reuse for the update or delete.

getIndexConglomerateNumber

long getIndexConglomerateNumber()
Get the conglomerate number of the index, if any, that has already been opened for scaning for an update or delete. (Saves opening the ScanController twice.)

Returns:
The conglomerate number, if available, to use for the update.

setIndexConglomerateNumber

void setIndexConglomerateNumber(long indexConglomerateNumber)
Set the conglomerate number of the index to be used for an update or delete, when scanning an index that will also be updated (Saves opening the ScanController twice.)

Parameters:
indexConglomerateNumber - The conglomerate number of the index to reuse for the update or delete.

clearIndexScanInfo

void clearIndexScanInfo()
Clear the info for the index to be re-used for update/delete. (ScanController and conglomerate number.)


setForCreateTable

void setForCreateTable()
Mark the Activation as being for create table. (NOTE: We can do certain optimizations for create table that we can't do for other DDL.)


getForCreateTable

boolean getForCreateTable()
Get whether or not this activation is for create table. (NOTE: We can do certain optimizations for create table that we can't do for other DDL.)

Returns:
Whether or not this activation is for create table.

setDDLTableDescriptor

void setDDLTableDescriptor(TableDescriptor td)
Save the TableDescriptor for the target of DDL so that it can be passed between the various ConstantActions during execution.


getDDLTableDescriptor

TableDescriptor getDDLTableDescriptor()
Get the TableDescriptor for the target of DDL.

Returns:
The TableDescriptor for the target of DDL.

setMaxRows

void setMaxRows(int maxRows)
Set the maximum # of rows. (# of rows that can be returned by a ResultSet. 0 means no limit.)

Parameters:
maxRows - Maximum # of rows. (0 means no limit.)

getMaxRows

int getMaxRows()
Get the maximum # of rows. (# of rows that can be returned by a ResultSet. 0 means no limit.)

Returns:
Maximum # of rows. (0 means no limit.)

isCursorActivation

boolean isCursorActivation()
Is this Activation for a cursor?

Returns:
Whether or not this Activation is for a cursor.

setTargetVTI

void setTargetVTI(java.sql.ResultSet targetVTI)
Save the ResultSet for the target of an update/delete to a VTI.


getTargetVTI

java.sql.ResultSet getTargetVTI()
Get the ResultSet for the target of an update/delete to a VTI.

Returns:
The ResultSet for the target of an update/delete to a VTI.

getConstantAction

ConstantAction getConstantAction()

setParentResultSet

void setParentResultSet(TemporaryRowHolder rs,
                        java.lang.String resultSetId)

getParentResultSet

java.util.Vector getParentResultSet(java.lang.String resultSetId)
get the reference to parent table ResultSets, that will be needed by the referential action dependent table scans.


clearParentResultSets

void clearParentResultSets()

getParentResultSets

java.util.Hashtable getParentResultSets()

setForUpdateIndexScan

void setForUpdateIndexScan(CursorResultSet forUpdateResultSet)
beetle 3865: updateable cursor using index. A way of communication between cursor activation and update activation.


getForUpdateIndexScan

CursorResultSet getForUpdateIndexScan()

getDynamicResults

java.sql.ResultSet[][] getDynamicResults()
Return the set of dynamical created result sets, for procedures. Base implementation returns null, a generated class for a procedure overwrites this with a real implementation.

Returns:
null if no dynamic results exists. Otherwise an array of ResultSet arrays, each of length one containing null or a reference to a ResultSet.

getMaxDynamicResults

int getMaxDynamicResults()
Return the maximum number of dynamical created result sets from the procedure definition. Base implementation returns 0, a generated class for a procedure overwrites this with a real implementation.


getSQLSessionContextForChildren

SQLSessionContext getSQLSessionContextForChildren()
Get the current SQL session context if in a nested connection of a stored routine or in a substatement.


setupSQLSessionContextForChildren

SQLSessionContext setupSQLSessionContextForChildren(boolean push)
Set up and return the current SQL session context for all immediately nested connections stemming from the call or function invocation of the statement corresponding to this activation (push=true) or for a substatement, which shares the parents statement's session context (push=false).

Parameters:
push - true if used to push a new connection context

setParentActivation

void setParentActivation(Activation a)
This activation is created in a dynamic call context or a substatement execution context, chain its parent statements activation..


getParentActivation

Activation getParentActivation()
This activation is created in a dynamic call context, or substatement execution context; get its caller's or superstatement's activation.

Returns:
The caller's activation

Built on Thu 2011-03-10 11:54:14+0000, from revision ???

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