Class ConstantActionActivation

java.lang.Object

org.apache.derby.impl.sql.execute.BaseActivation

org.apache.derby.impl.sql.execute.ConstantActionActivation

All Implemented Interfaces:

Dependable, GeneratedByteCode, Activation, Dependent, CursorActivation

public final class ConstantActionActivation
extends BaseActivation

A pre-compiled activation that supports a single ResultSet with a single constant action. All the execution logic is contained in the constant action.

At compile time for DDL statements this class will be picked as the implementation of Activation. The language PreparedStatement will contain the ConstantAction created at compiled time. At execute time this class then fetches a language ResultSet using ResultSetFactory.getDDLResultSet and executing the ResultSet will invoke the execute on the ConstantAction.

Field Summary

Fields inherited from class BaseActivation

closed, cm, indexOfSessionTableNamesInSavedObjects, numSubqueries, parentResultSets, preStmt, pvs, raParentResultSets, resultDescription, resultSet, row, UUIDString, UUIDValue

Fields inherited from interface 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

Constructor Summary

Constructors

Constructor	Description
ConstantActionActivation()

Method Summary

Modifier and Type	Method	Description
protected ResultSet	createResultSet()	Create the ResultSet tree for this statement.
void	postConstructor()	Called by the class manager just after calling setGC().
protected boolean	shouldWeCheckRowCounts()	Always return false since constant actions don't need recompilation when the row counts change.

Methods inherited from class BaseActivation

addWarning, allocateQualArray, checkIfThisActivationHasHoldCursor, checkPositionedStatement, checkStatementValidity, clearCurrentRow, clearHeapConglomerateController, clearIndexScanInfo, clearParentResultSets, clearWarnings, close, closeActivationAction, decorateResultSet, e0, e1, e2, e3, e4, e5, e6, e7, e8, e9, execute, getAutoGeneratedKeysColumnIndexes, getAutoGeneratedKeysColumnNames, getAutoGeneratedKeysResultsetMode, getCalendar, getClassType, getColumnFromRow, getConstantAction, getContextManager, getCurrentConnection, getCurrentRow, getCurrentValueAndAdvance, getCursorName, getCursorResultSet, getDataValueFactory, getDB2Length, getDDLTableDescriptor, getDependableFinder, getDynamicResults, getExecutionFactory, getForCreateTable, getForUpdateIndexScan, getGC, getHeapConglomerateController, getIndexConglomerateNumber, getIndexScanController, getLanguageConnectionContext, getMaxDynamicResults, getMaxRows, getMethod, getMonitor, getNumSubqueries, getObjectID, getObjectName, getParameter, getParameterValueSet, getParentActivation, getParentResultSet, getParentResultSetKeys, getPreparedStatement, getResultDescription, getResultSet, getResultSetFactory, getResultSetHoldability, getRowLocationTemplate, getScrollable, getSetAutoincrementValue, getSQLSessionContextForChildren, getTargetResultSet, getTargetVTI, getTransactionController, getWarnings, informOfRowCount, initFromContext, isClosed, isCursorActivation, isInUse, isPersistent, isSingleExecution, isValid, makeInvalid, markUnused, materializeResultSetIfPossible, nullToPrimitiveTest, popConstantAction, prepareToInvalidate, pushConstantAction, reinit, reinitializeQualifiers, reset, setAutoGeneratedKeysResultsetInfo, setColumnPosition, setCurrentRow, setCursorName, setDDLTableDescriptor, setForCreateTable, setForUpdateIndexScan, setGC, setHeapConglomerateController, setIndexConglomerateNumber, setIndexScanController, setMaxRows, setParameters, setParameterValueSet, setParentActivation, setParentResultSet, setQualifier, setResultSetHoldability, setSingleExecution, setTargetVTI, setupActivation, setupSQLSessionContextForChildren, throwIfClosed, throwIfMissingParms

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ConstantActionActivation

public ConstantActionActivation()

Method Details

shouldWeCheckRowCounts

protected boolean shouldWeCheckRowCounts()

Always return false since constant actions don't need recompilation when the row counts change.

Overrides:

shouldWeCheckRowCounts in class BaseActivation

Returns:

true if the row counts should be checked, false otherwise

createResultSet

protected ResultSet createResultSet()
                             throws StandardException

Description copied from class: BaseActivation

Create the ResultSet tree for this statement.

Specified by:

createResultSet in class BaseActivation

Returns:

the root of the ResultSet tree for this statement

Throws:

StandardException - standard error policy

postConstructor

public void postConstructor()

Description copied from interface: GeneratedByteCode

Called by the class manager just after calling setGC().