Package org.apache.derby.impl.sql.compile

Class FromBaseTable

java.lang.Object

org.apache.derby.impl.sql.compile.QueryTreeNode

org.apache.derby.impl.sql.compile.ResultSetNode

org.apache.derby.impl.sql.compile.FromTable

org.apache.derby.impl.sql.compile.FromBaseTable

All Implemented Interfaces:

Optimizable, Visitable

class FromBaseTable
extends FromTable

A FromBaseTable represents a table in the FROM list of a DML statement, as distinguished from a FromSubquery, which represents a subquery in the FROM list. A FromBaseTable may actually represent a view. During parsing, we can't distinguish views from base tables. During binding, when we find FromBaseTables that represent views, we replace them with FromSubqueries. By the time we get to code generation, all FromSubqueries have been eliminated, and all FromBaseTables will represent only true base tables.

Positioned Update: Currently, all columns of an updatable cursor are selected to deal with a positioned update. This is because we don't know what columns will ultimately be needed from the UpdateNode above us. For example, consider:

        get c as 'select cint from t for update of ctinyint'
  update t set ctinyint = csmallint

 

Ideally, the cursor only selects cint. Then, something akin to an IndexRowToBaseRow is generated to take the CursorResultSet and get the appropriate columns out of the base table from the RowLocation returned by the cursor. Then the update node can generate the appropriate NormalizeResultSet (or whatever else it might need) to get things into the correct format for the UpdateResultSet. See CurrentOfNode for more information.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.derby.impl.sql.compile.ResultSetNode

ResultSetNode.QueryExpressionClauses

Field Summary

Fields

Modifier and Type	Field	Description
private boolean	authorizeSYSUSERS
(package private) ConglomerateDescriptor	baseConglomerateDescriptor
(package private) PredicateList	baseTableRestrictionList	Restriction as a PredicateList
(package private) int	bulkFetch
(package private) boolean	bulkFetchTurnedOff
private java.lang.String[]	columnNames
(package private) ConglomerateDescriptor[]	conglomDescs
(package private) static int	DELETE
private JBitSet	dependencyMap
private boolean	distinctScan
private boolean	existsBaseTable
private int[]	fkColArray
private long	fkIndexConglomId
private boolean	getUpdateLocks
private boolean	gotRowCount
private boolean	hasCheckedIndexStats	Whether or not we have checked the index statistics for staleness.
private boolean	isNotExists
(package private) boolean	multiProbing
(package private) PredicateList	nonBaseTableRestrictionList
(package private) PredicateList	nonStoreRestrictionList
private boolean	raDependentScan	Information for dependent table scan for Referential Actions
private java.lang.String	raParentResultSetId
private FormatableBitSet	referencedCols
(package private) PredicateList	requalificationRestrictionList
(package private) PredicateList	restrictionList
private long	rowCount
private java.lang.String	rowLocationColumnName
private double	singleScanRowCount
private boolean	specialMaxScan
(package private) PredicateList	storeRestrictionList
(package private) TableDescriptor	tableDescriptor
(package private) TableName	tableName
private java.lang.String	targetTableUUIDString
private ResultColumnList	templateColumns
(package private) static int	UNSET
(package private) static int	UPDATE
(package private) int	updateOrDelete
private boolean	validatingCheckConstraint

Fields inherited from class org.apache.derby.impl.sql.compile.FromTable

ADD_PLAN, bestAccessPath, bestCostEstimate, bestSortAvoidancePath, correlationName, corrTableName, currentAccessPath, hashKeyColumns, initialCapacity, level, LOAD_PLAN, loadFactor, maxCapacity, origTableName, REMOVE_PLAN, tableNumber, tableProperties, trulyTheBestAccessPath, userSpecifiedJoinStrategy

Fields inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode

AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_CYCLE, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX

Constructor Summary

Constructors

Constructor	Description
FromBaseTable(TableName tableName, java.lang.String correlationName, int updateOrDelete, ResultColumnList derivedRCL, ContextManager cm)	Initializer for a table in a FROM list.
FromBaseTable(TableName tableName, java.lang.String correlationName, ResultColumnList derivedRCL, java.util.Properties tableProperties, ContextManager cm)	Constructor for a table in a FROM list.

Method Summary

Modifier and Type	Method	Description
(package private) void	acceptChildren(Visitor v)	Accept the visitor for all visitable children of this node.
(package private) ResultColumnList	addColsToList(ResultColumnList inputRcl, FormatableBitSet colsWeWant)	Augment the RCL to include the columns in the FormatableBitSet.
(package private) void	adjustForSortElimination()	Notify the underlying result set tree that the optimizer has chosen to "eliminate" a sort.
(package private) void	adjustForSortElimination(RequiredRowOrdering rowOrdering)	Same goal as adjustForSortElimination above, but this version takes a RequiredRowOrdering to allow nodes to adjust based on the ORDER BY clause, if needed.
private long	baseRowCount()
(package private) void	bindExpressions(FromList fromListParam)	Bind the expressions in this FromBaseTable.
(package private) ResultSetNode	bindNonVTITables(DataDictionary dataDictionary, FromList fromListParam)	Bind the table in this FromBaseTable.
(package private) void	bindResultColumns(FromList fromListParam)	Bind the result columns of this ResultSetNode when there is no base table to bind them to.
private TableDescriptor	bindTableDescriptor()	Bind the table descriptor for this table.
protected boolean	canBeOrdered()	Tell super-class that this Optimizable can be ordered
(package private) ResultSetNode	changeAccessPath()	The optimizer's decision on the access path for a result set may require the generation of extra result sets.
(package private) void	clearDependency(java.util.List<java.lang.Integer> locations)	Clear the bits from the dependency map when join nodes are flattened
int	convertAbsoluteToRelativeColumnPosition(int absolutePosition)	Convert an absolute to a relative 0-based column position.
protected boolean	cursorTargetTable()	Is this a table that has a FOR UPDATE clause?
(package private) void	disableBulkFetch()	Turn off bulk fetch
(package private) void	doSpecialMaxScan()	Do a special scan for max.
CostEstimate	estimateCost(OptimizablePredicateList predList, ConglomerateDescriptor cd, CostEstimate outerCost, Optimizer optimizer, RowOrdering rowOrdering)	Estimate the cost of scanning this FromBaseTable using the given predicate list with the given conglomerate.
boolean	forUpdate()	Return true if this is the target table of an update
(package private) void	generate(ActivationClassBuilder acb, MethodBuilder mb)	Generation on a FromBaseTable creates a scan on the optimizer-selected conglomerate.
private void	generateDistinctScan(ExpressionClassBuilder acb, MethodBuilder mb)
private void	generateMaxSpecialResultSet(ExpressionClassBuilder acb, MethodBuilder mb)
private void	generateRefActionDependentTableScan(ExpressionClassBuilder acb, MethodBuilder mb)	Generation on a FromBaseTable for a referential action dependent table.
(package private) void	generateResultSet(ExpressionClassBuilder acb, MethodBuilder mb)	Generation on a FromBaseTable for a SELECT.
protected ResultSetNode	genProjectRestrict(int numTables)	Put a ProjectRestrictNode on top of each FromTable in the FromList.
(package private) ResultColumnList	genResultColList()	Build a ResultColumnList based on all of the columns in this FromBaseTable.
(package private) ResultColumnList	getAllResultColumns(TableName allTableName)	Return a ResultColumnList with all of the columns in this table.
private StoreCostController	getBaseCostController()
java.lang.String	getBaseTableName()	Get the table name of this Optimizable.
private void	getConglomDescs()
private int	getDefaultBulkFetch()
(package private) boolean	getExistsBaseTable()	Does this FBT represent an EXISTS FBT.
(package private) java.lang.String	getExposedName()	Get the exposed name for this table, which is the name that can be used to refer to it in the rest of the query.
(package private) TableName	getExposedTableName()	Get the exposed table name for this table, which is the name that can be used to refer to it in the rest of the query.
(package private) CostEstimate	getFinalCostEstimate()	Get the final CostEstimate for this ResultSetNode.
private ConglomerateDescriptor	getFirstConglom()
(package private) FromTable	getFromTableByName(java.lang.String name, java.lang.String schemaName, boolean exactMatch)	Determine whether or not the specified name is an exposed name in the current query block.
(package private) ResultColumn	getMatchingColumn(ColumnReference columnReference)	Try to find a ResultColumn in the table represented by this FromBaseTable that matches the name in the given ColumnReference.
private ConglomerateDescriptor	getNextConglom(ConglomerateDescriptor currCD)
private DataValueDescriptor[]	getRowTemplate(ConglomerateDescriptor cd, StoreCostController scc)
private int	getScanArguments(ExpressionClassBuilder acb, MethodBuilder mb)
private StoreCostController	getStoreCostController(ConglomerateDescriptor cd)
TableDescriptor	getTableDescriptor()	Get the table descriptor for this table (if any).
(package private) TableName	getTableName()	Return a TableName node representing this FromTable.
(package private) TableName	getTableNameField()	Return the table name for this table.
private java.lang.String	getUserSpecifiedIndexName()
int	initialCapacity()	Return the initial capacity of the hash table, for hash join strategy
boolean	isBaseTable()	Tell whether this Optimizable represents a base table
boolean	isCoveringIndex(ConglomerateDescriptor cd)	Return whether or not this is a covering index.
boolean	isMaterializable()	Tell whether this Optimizable is materializable
(package private) boolean	isNotExists()	Return whether or not this is actually a EBT for NOT EXISTS.
(package private) boolean	isOneRowResultSet()	Return whether or not the underlying ResultSet tree will return a single row, at most.
(package private) boolean	isOneRowResultSet(OptimizablePredicateList predList)
private boolean	isOneRowResultSet(ConglomerateDescriptor cd, OptimizablePredicateList predList)	Is this a one-row result set with the given conglomerate descriptor?
boolean	isOneRowScan()	Will the optimizable return at most 1 row per scan?
private boolean	isOrdered(ColumnReference[] crs, ConglomerateDescriptor cd)	Return whether or not this index is ordered on a permutation of the specified columns.
(package private) boolean	isOrderedOn(ColumnReference[] crs, boolean permuteOrdering, java.util.List<FromBaseTable> fbtHolder)	Return whether or not the underlying ResultSet tree is ordered on the specified columns.
(package private) boolean	isPossibleDistinctScan(java.util.Set<BaseColumnNode> distinctColumns)	Is it possible to do a distinct scan on this ResultSet tree.
private boolean	isStrictlyOrdered(ColumnReference[] crs, ConglomerateDescriptor cd)	Return whether or not this index is ordered on a permutation of the specified columns.
boolean	isTargetTable()	Is the optimizable the target table of an update or delete?
private boolean	isValidatingCheckConstraint()
boolean	legalJoinOrder(JBitSet assignedTableMap)	Can this Optimizable appear at the current location in the join order.
float	loadFactor()	Return the load factor of the hash table, for hash join strategy
(package private) boolean	LOJ_reorderable(int numTables)	no LOJ reordering for base table.
(package private) JBitSet	LOJgetReferencedTables(int numTables)
private int	mapAbsoluteToRelativeColumnPosition(int absolutePosition)	Convert an absolute to a relative 0-based column position.
private ResultSetNode	mapTableAsVTI(TableDescriptor td, java.lang.String correlationName, ResultColumnList resultColumns, java.util.Properties tableProperties, ContextManager cm)	Return a node that represents invocation of the virtual table for the given table descriptor.
(package private) boolean	markAsCursorTargetTable()	Mark this ResultSetNode as the target table of an updatable cursor.
(package private) void	markForDistinctScan()	Mark the underlying scan as a distinct scan.
(package private) void	markUpdated(ResultColumnList updateColumns)	Mark as updatable all the columns in the result column list of this FromBaseTable that match the columns in the given update column list.
boolean	memoryUsageOK(double rowCount, int maxMemoryPerTable)
private ResultColumnList	newResultColumns(ResultColumnList oldColumns, ConglomerateDescriptor idxCD, ConglomerateDescriptor heapCD, boolean cloneRCs)	Create a new ResultColumnList to reflect the columns in the index described by the given ConglomerateDescriptor.
boolean	nextAccessPath(Optimizer optimizer, OptimizablePredicateList predList, RowOrdering rowOrdering)	Choose the next access path to evaluate for this Optimizable.
CostEstimate	optimizeIt(Optimizer optimizer, OptimizablePredicateList predList, CostEstimate outerCost, RowOrdering rowOrdering)	Choose the best access path for this Optimizable.
(package private) ResultSetNode	preprocess(int numTables, GroupByList gbl, FromList fromList)	Preprocess a ResultSetNode - this currently means: o Generating a referenced table map for each ResultSetNode.
void	pullOptPredicates(OptimizablePredicateList optimizablePredicates)	Pull all the OptimizablePredicates from this Optimizable and put them in the given OptimizablePredicateList.
private void	pushIndexName(ConglomerateDescriptor cd, MethodBuilder mb)
boolean	pushOptPredicate(OptimizablePredicate optimizablePredicate)	Push an OptimizablePredicate down, if this node accepts it.
private boolean	qualifiesForStatisticsUpdateCheck(TableDescriptor td)	Tells if the given table qualifies for a statistics update check in the current configuration.
boolean	referencesSessionSchema()	Return true if the node references SESSION schema tables (temporary or permanent)
(package private) boolean	referencesTarget(java.lang.String name, boolean baseTable)	Search to see if a query references the specifed table name.
private double	scanCostAfterSelectivity(double originalScanCost, double initialPositionCost, double selectivity, boolean anotherIndexUnique)
(package private) void	setExistsBaseTable(boolean existsBaseTable, JBitSet dependencyMap, boolean isNotExists)	Set whether or not this FBT represents an EXISTS FBT.
private void	setLockingBasedOnThreshold(Optimizer optimizer, double rowsTouched)
(package private) void	setRefActionInfo(long fkIndexConglomId, int[] fkColArray, java.lang.String parentResultSetId, boolean dependentScan)	set the Information gathered from the parent table that is required to perform a referential action on dependent table.
(package private) void	setRowLocationColumnName(java.lang.String rowLocationColumnName)	Set the name of the row location column
(package private) void	setTableProperties(java.util.Properties tableProperties)	Set the table properties for this table.
void	startOptimizing(Optimizer optimizer, RowOrdering rowOrdering)	Begin the optimization process for this Optimizable.
protected boolean	supersetOfUniqueIndex(boolean[] eqCols)	Determine whether or not the columns marked as true in the passed in array are a superset of any unique index on this table.
protected boolean	supersetOfUniqueIndex(JBitSet[] tableColMap)	Determine whether or not the columns marked as true in the passed in join table matrix are a superset of any single column unique index on this table.
java.lang.String	toString()	Convert this object to a String.
double	uniqueJoin(OptimizablePredicateList predList)	Does this optimizable have a uniqueness condition on the given predicate list, and if so, how many unique keys will be returned per scan.
(package private) int	updateTargetLockMode()	Get the lock mode for the target table heap of an update or delete statement.
void	verifyProperties(DataDictionary dDictionary)	Verify that the Properties list with optimizer overrides, if specified, is valid

Methods inherited from class org.apache.derby.impl.sql.compile.FromTable

assignCostEstimate, columnsAreUpdatable, considerSortAvoidancePath, decrementLevel, feasibleJoinStrategy, fillInReferencedTableMap, flatten, getBestAccessPath, getBestSortAvoidancePath, getCorrelationName, getCostEstimate, getCurrentAccessPath, getLevel, getMergeTableID, getName, getNumColumnsReturned, getOrigTableName, getProperties, getResultColumnsForList, getSchemaDescriptor, getSchemaDescriptor, getScratchCostEstimate, getTableNumber, getTrulyTheBestAccessPath, getUserSpecifiedJoinStrategy, hashKeyColumns, hasLargeObjectColumns, hasTableNumber, initAccessPaths, isFlattenableJoinNode, isJoinColumnForRightOuterJoin, markUpdatableByCursor, maxCapacity, modifyAccessPath, needsSpecialRCLBinding, optimizeSubqueries, pushExpressions, rememberAsBest, rememberJoinStrategyAsBest, rememberSortAvoidancePath, resetJoinStrategies, setCostEstimateCost, setHashKeyColumns, setLevel, setMergeTableID, setOrigTableName, setProperties, setTableNumber, supportsMultipleInstantiations, tellRowOrderingAboutConstantColumns, transformOuterJoins, updateBestPlanMap

Methods inherited from class org.apache.derby.impl.sql.compile.ResultSetNode

addNewPredicate, assignResultSetNumber, bindExpressionsWithTables, bindResultColumns, bindTargetExpressions, bindUntypedNullsToResultColumns, bindVTITables, columnTypesAndLengthsMatch, considerMaterialization, enhanceRCLForInsert, ensurePredicateList, flattenableInFromSubquery, generateNormalizationResultSet, genProjectRestrict, genProjectRestrictForReordering, getCandidateFinalCostEstimate, getCostEstimate, getCursorTargetTable, getFromList, getNewCostEstimate, getOptimizer, getOptimizerImpl, getRCLForInsert, getReferencedTableMap, getResultColumns, getResultSetNumber, getScratchCostEstimate, isCursorTargetTable, isInsertSource, isStatementResultSet, isUpdatableCursor, makeResultDescription, makeResultDescriptors, markStatementResultSet, modifyAccessPaths, modifyAccessPaths, notCursorTargetTable, notFlattenableJoin, numDistinctAggregates, optimize, parseDefault, performMaterialization, printQueryExpressionSuffixClauses, printSubNodes, projectResultColumns, pushOffsetFetchFirst, pushOrderByList, pushQueryExpressionSuffix, rejectParameters, rejectXMLValues, renameGeneratedResultNames, replaceOrForbidDefaults, returnsAtMostOneRow, setCandidateFinalCostEstimate, setCostEstimate, setCursorTargetTable, setInsertSource, setOptimizer, setReferencedTableMap, setResultColumns, setResultSetNumber, setResultToBooleanTrueNode, setScratchCostEstimate, setTableConstructorTypes, subqueryReferencesTarget, verifySelectStarSubquery

Methods inherited from class org.apache.derby.impl.sql.compile.QueryTreeNode

accept, addTag, addUDTUsagePriv, addUDTUsagePriv, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, convertDefaultNode, copyTagsFrom, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContext, getContextManager, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getLongProperty, getNullNode, getOffsetOrderedNodes, getOptimizerFactory, getOptimizerTracer, getParameterTypes, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, getUDTDesc, isAtomic, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, optimizerTracingIsOn, orReliability, parseSearchCondition, parseStatement, printLabel, resolveTableToSynonym, setBeginOffset, setEndOffset, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.derby.iapi.sql.compile.Optimizable

getDataDictionary, getOptimizerTracer, getReferencedTableMap, getResultSetNumber, optimizerTracingIsOn

Methods inherited from interface org.apache.derby.iapi.sql.compile.Visitable

accept, addTag, taggedWith

Field Detail

UNSET

static final int UNSET

See Also:

Constant Field Values

hasCheckedIndexStats

private boolean hasCheckedIndexStats

Whether or not we have checked the index statistics for staleness. Used to avoid performing the check multiple times per compilation.

tableName

TableName tableName

tableDescriptor

TableDescriptor tableDescriptor

baseConglomerateDescriptor

ConglomerateDescriptor baseConglomerateDescriptor

conglomDescs

ConglomerateDescriptor[] conglomDescs

updateOrDelete

int updateOrDelete

bulkFetch

int bulkFetch

targetTableUUIDString

private java.lang.String targetTableUUIDString

validatingCheckConstraint

private boolean validatingCheckConstraint

bulkFetchTurnedOff

boolean bulkFetchTurnedOff

multiProbing

boolean multiProbing

singleScanRowCount

private double singleScanRowCount

referencedCols

private FormatableBitSet referencedCols

templateColumns

private ResultColumnList templateColumns

columnNames

private java.lang.String[] columnNames

specialMaxScan

private boolean specialMaxScan

distinctScan

private boolean distinctScan

raDependentScan

private boolean raDependentScan

Information for dependent table scan for Referential Actions

raParentResultSetId

private java.lang.String raParentResultSetId

fkIndexConglomId

private long fkIndexConglomId

fkColArray

private int[] fkColArray

baseTableRestrictionList

PredicateList baseTableRestrictionList

Restriction as a PredicateList

nonBaseTableRestrictionList

PredicateList nonBaseTableRestrictionList

restrictionList

PredicateList restrictionList

storeRestrictionList

PredicateList storeRestrictionList

nonStoreRestrictionList

PredicateList nonStoreRestrictionList

requalificationRestrictionList

PredicateList requalificationRestrictionList

UPDATE

static final int UPDATE

See Also:

Constant Field Values

DELETE

static final int DELETE

See Also:

Constant Field Values

existsBaseTable

private boolean existsBaseTable

isNotExists

private boolean isNotExists

dependencyMap

private JBitSet dependencyMap

getUpdateLocks

private boolean getUpdateLocks

authorizeSYSUSERS

private boolean authorizeSYSUSERS

rowLocationColumnName

private java.lang.String rowLocationColumnName

gotRowCount

private boolean gotRowCount

rowCount

private long rowCount

Constructor Detail

FromBaseTable

FromBaseTable(TableName tableName,
              java.lang.String correlationName,
              ResultColumnList derivedRCL,
              java.util.Properties tableProperties,
              ContextManager cm)

Constructor for a table in a FROM list. Parameters are as follows:

Parameters:

tableName - The name of the table

correlationName - The correlation name

derivedRCL - The derived column list

tableProperties - The Properties list associated with the table.

cm - The context manager

FromBaseTable

FromBaseTable(TableName tableName,
              java.lang.String correlationName,
              int updateOrDelete,
              ResultColumnList derivedRCL,
              ContextManager cm)

Initializer for a table in a FROM list. Parameters are as follows:

Parameters:

tableName - The name of the table

correlationName - The correlation name

updateOrDelete - Table is being updated/deleted from.

derivedRCL - The derived column list

cm - The context manager

Method Detail

setRowLocationColumnName

void setRowLocationColumnName(java.lang.String rowLocationColumnName)

Set the name of the row location column

LOJ_reorderable

boolean LOJ_reorderable(int numTables)
                 throws StandardException

no LOJ reordering for base table.

Overrides:

LOJ_reorderable in class FromTable

Throws:

StandardException

LOJgetReferencedTables

JBitSet LOJgetReferencedTables(int numTables)
                        throws StandardException

Overrides:

LOJgetReferencedTables in class ResultSetNode

Throws:

StandardException

nextAccessPath

public boolean nextAccessPath(Optimizer optimizer,
                              OptimizablePredicateList predList,
                              RowOrdering rowOrdering)
                       throws StandardException

Description copied from interface: Optimizable

Choose the next access path to evaluate for this Optimizable.

Specified by:

nextAccessPath in interface Optimizable

Overrides:

nextAccessPath in class FromTable

Parameters:

optimizer - Optimizer to use.

predList - The predicate list for this optimizable. The optimizer always passes null, and it is up to the optimizable object to pass along its own predicate list, if appropriate, when delegating this method.

rowOrdering - The row ordering for all the outer tables in the join order. This method will add the ordering of the next access path to the given RowOrdering.

Returns:

true means another access path was chosen, false means no more access paths to evaluate.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.nextAccessPath(org.apache.derby.iapi.sql.compile.Optimizer, org.apache.derby.iapi.sql.compile.OptimizablePredicateList, org.apache.derby.iapi.sql.compile.RowOrdering)

canBeOrdered

protected boolean canBeOrdered()

Tell super-class that this Optimizable can be ordered

Overrides:

canBeOrdered in class FromTable

optimizeIt

public CostEstimate optimizeIt(Optimizer optimizer,
                               OptimizablePredicateList predList,
                               CostEstimate outerCost,
                               RowOrdering rowOrdering)
                        throws StandardException

Description copied from interface: Optimizable

Choose the best access path for this Optimizable.

Specified by:

optimizeIt in interface Optimizable

Overrides:

optimizeIt in class FromTable

Parameters:

optimizer - Optimizer to use.

predList - The predicate list to optimize against

outerCost - The CostEstimate for the outer tables in the join order, telling how many times this Optimizable will be scanned.

rowOrdering - The row ordering for all the tables in the join order, including this one.

Returns:

The optimizer's estimated cost of the best access path.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.optimizeIt(org.apache.derby.iapi.sql.compile.Optimizer, org.apache.derby.iapi.sql.compile.OptimizablePredicateList, org.apache.derby.iapi.sql.compile.CostEstimate, org.apache.derby.iapi.sql.compile.RowOrdering)

getTableDescriptor

public TableDescriptor getTableDescriptor()

Description copied from interface: Optimizable

Get the table descriptor for this table (if any). Only base tables have table descriptors - for the rest of the optimizables, this method returns null.

Specified by:

getTableDescriptor in interface Optimizable

Overrides:

getTableDescriptor in class FromTable

See Also:

Optimizable.getTableDescriptor()

isMaterializable

public boolean isMaterializable()
                         throws StandardException

Description copied from interface: Optimizable

Tell whether this Optimizable is materializable

Specified by:

isMaterializable in interface Optimizable

Overrides:

isMaterializable in class FromTable

Throws:

StandardException - Thrown on error

See Also:

Optimizable.isMaterializable()

pushOptPredicate

public boolean pushOptPredicate(OptimizablePredicate optimizablePredicate)
                         throws StandardException

Description copied from interface: Optimizable

Push an OptimizablePredicate down, if this node accepts it.

Specified by:

pushOptPredicate in interface Optimizable

Overrides:

pushOptPredicate in class FromTable

Parameters:

optimizablePredicate - OptimizablePredicate to push down.

Returns:

Whether or not the predicate was pushed down.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.pushOptPredicate(org.apache.derby.iapi.sql.compile.OptimizablePredicate)

pullOptPredicates

public void pullOptPredicates(OptimizablePredicateList optimizablePredicates)
                       throws StandardException

Description copied from interface: Optimizable

Pull all the OptimizablePredicates from this Optimizable and put them in the given OptimizablePredicateList.

Specified by:

pullOptPredicates in interface Optimizable

Overrides:

pullOptPredicates in class FromTable

Parameters:

optimizablePredicates - The list to put the pulled predicates in.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.pullOptPredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList)

isCoveringIndex

public boolean isCoveringIndex(ConglomerateDescriptor cd)
                        throws StandardException

Description copied from interface: Optimizable

Return whether or not this is a covering index. We expect to call this during generation, after access path selection is complete.

Specified by:

isCoveringIndex in interface Optimizable

Overrides:

isCoveringIndex in class FromTable

Parameters:

cd - ConglomerateDesriptor for index to consider

Returns:

boolean Whether or not this is a covering index.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.isCoveringIndex(org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor)

verifyProperties

public void verifyProperties(DataDictionary dDictionary)
                      throws StandardException

Description copied from interface: Optimizable

Verify that the Properties list with optimizer overrides, if specified, is valid

Specified by:

verifyProperties in interface Optimizable

Overrides:

verifyProperties in class FromTable

Parameters:

dDictionary - The DataDictionary to use.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.verifyProperties(org.apache.derby.iapi.sql.dictionary.DataDictionary)

isValidatingCheckConstraint

private boolean isValidatingCheckConstraint()
                                     throws StandardException

Throws:

StandardException

getBaseTableName

public java.lang.String getBaseTableName()

Description copied from interface: Optimizable

Get the table name of this Optimizable. Only base tables have table names (by the time we use this method, all views will have been resolved).

Specified by:

getBaseTableName in interface Optimizable

Overrides:

getBaseTableName in class FromTable

See Also:

Optimizable.getBaseTableName()

startOptimizing

public void startOptimizing(Optimizer optimizer,
                            RowOrdering rowOrdering)

Description copied from interface: Optimizable

Begin the optimization process for this Optimizable. This can be called many times for an Optimizable while optimizing a query - it will typically be called every time the Optimizable is placed in a potential join order.

Specified by:

startOptimizing in interface Optimizable

Overrides:

startOptimizing in class FromTable

See Also:

Optimizable.startOptimizing(org.apache.derby.iapi.sql.compile.Optimizer, org.apache.derby.iapi.sql.compile.RowOrdering)

convertAbsoluteToRelativeColumnPosition

public int convertAbsoluteToRelativeColumnPosition(int absolutePosition)

Description copied from interface: Optimizable

Convert an absolute to a relative 0-based column position. This is useful when generating qualifiers for partial rows from the store.

Specified by:

convertAbsoluteToRelativeColumnPosition in interface Optimizable

Overrides:

convertAbsoluteToRelativeColumnPosition in class FromTable

Parameters:

absolutePosition - The absolute 0-based column position for the column.

Returns:

The relative 0-based column position for the column.

See Also:

Optimizable.convertAbsoluteToRelativeColumnPosition(int)

estimateCost

public CostEstimate estimateCost(OptimizablePredicateList predList,
                                 ConglomerateDescriptor cd,
                                 CostEstimate outerCost,
                                 Optimizer optimizer,
                                 RowOrdering rowOrdering)
                          throws StandardException

Estimate the cost of scanning this FromBaseTable using the given predicate list with the given conglomerate.

If the table contains little data, the cost estimate might be adjusted to make it more likely that an index scan will be preferred to a table scan, and a unique index will be preferred to a non-unique index. Even though such a plan may be slightly suboptimal when seen in isolation, using indexes, unique indexes in particular, needs fewer locks and allows more concurrency.

Specified by:

estimateCost in interface Optimizable

Overrides:

estimateCost in class FromTable

Parameters:

predList - The predicate list to optimize against

cd - The conglomerate descriptor to get the cost of

outerCost - The estimated cost of the part of the plan outer to this optimizable.

optimizer - The optimizer to use to help estimate the cost

rowOrdering - The row ordering for all the tables in the join order, including this one.

Returns:

The estimated cost of doing the scan

Throws:

StandardException - Thrown on error

See Also:

Optimizable.estimateCost(org.apache.derby.iapi.sql.compile.OptimizablePredicateList, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor, org.apache.derby.iapi.sql.compile.CostEstimate, org.apache.derby.iapi.sql.compile.Optimizer, org.apache.derby.iapi.sql.compile.RowOrdering)

scanCostAfterSelectivity

private double scanCostAfterSelectivity(double originalScanCost,
                                        double initialPositionCost,
                                        double selectivity,
                                        boolean anotherIndexUnique)
                                 throws StandardException

Throws:

StandardException

setLockingBasedOnThreshold

private void setLockingBasedOnThreshold(Optimizer optimizer,
                                        double rowsTouched)

isBaseTable

public boolean isBaseTable()

Description copied from interface: Optimizable

Tell whether this Optimizable represents a base table

Specified by:

isBaseTable in interface Optimizable

Overrides:

isBaseTable in class FromTable

See Also:

Optimizable.isBaseTable()

forUpdate

public boolean forUpdate()

Description copied from interface: Optimizable

Return true if this is the target table of an update

Specified by:

forUpdate in interface Optimizable

Overrides:

forUpdate in class FromTable

See Also:

Optimizable.forUpdate()

initialCapacity

public int initialCapacity()

Description copied from interface: Optimizable

Return the initial capacity of the hash table, for hash join strategy

Specified by:

initialCapacity in interface Optimizable

Overrides:

initialCapacity in class FromTable

See Also:

Optimizable.initialCapacity()

loadFactor

public float loadFactor()

Description copied from interface: Optimizable

Return the load factor of the hash table, for hash join strategy

Specified by:

loadFactor in interface Optimizable

Overrides:

loadFactor in class FromTable

See Also:

Optimizable.loadFactor()

memoryUsageOK

public boolean memoryUsageOK(double rowCount,
                             int maxMemoryPerTable)
                      throws StandardException

Specified by:

memoryUsageOK in interface Optimizable

Overrides:

memoryUsageOK in class FromTable

Returns:

true if the memory usage of the proposed access path is OK, false if not.

Throws:

StandardException - standard error policy

See Also:

Optimizable.memoryUsageOK(double, int)

isTargetTable

public boolean isTargetTable()

Description copied from interface: Optimizable

Is the optimizable the target table of an update or delete?

Specified by:

isTargetTable in interface Optimizable

Overrides:

isTargetTable in class FromTable

Returns:

Whether or not the optimizable the target table of an update or delete.

See Also:

Optimizable.isTargetTable()

uniqueJoin

public double uniqueJoin(OptimizablePredicateList predList)
                  throws StandardException

Description copied from interface: Optimizable

Does this optimizable have a uniqueness condition on the given predicate list, and if so, how many unique keys will be returned per scan.

Specified by:

uniqueJoin in interface Optimizable

Overrides:

uniqueJoin in class FromTable

Parameters:

predList - The predicate list to check

Returns:

<= 0 means there is no uniqueness condition > 0 means there is a uniqueness condition, and the return value is the number of rows per scan.

Throws:

StandardException - Thrown on error

See Also:

Optimizable.uniqueJoin(org.apache.derby.iapi.sql.compile.OptimizablePredicateList)

isOneRowScan

public boolean isOneRowScan()
                     throws StandardException

Description copied from interface: Optimizable

Will the optimizable return at most 1 row per scan?

Specified by:

isOneRowScan in interface Optimizable

Overrides:

isOneRowScan in class FromTable

Returns:

Whether or not the optimizable will return at most 1 row per scan?

Throws:

StandardException - Thrown on error

See Also:

Optimizable.isOneRowScan()

legalJoinOrder

public boolean legalJoinOrder(JBitSet assignedTableMap)

Description copied from interface: Optimizable

Can this Optimizable appear at the current location in the join order. In other words, have the Optimizable's dependencies been satisfied?

Specified by:

legalJoinOrder in interface Optimizable

Overrides:

legalJoinOrder in class FromTable

Parameters:

assignedTableMap - The tables that have been placed so far in the join order.

Returns:

Where or not this Optimizable can appear at the current location in the join order.

See Also:

Optimizable.legalJoinOrder(org.apache.derby.iapi.util.JBitSet)

toString

public java.lang.String toString()

Convert this object to a String. See comments in QueryTreeNode.java for how this should be done for tree printing.

Overrides:

toString in class FromTable

Returns:

This object as a String

getExistsBaseTable

boolean getExistsBaseTable()

Does this FBT represent an EXISTS FBT.

Returns:

Whether or not this FBT represents an EXISTS FBT.

setExistsBaseTable

void setExistsBaseTable(boolean existsBaseTable,
                        JBitSet dependencyMap,
                        boolean isNotExists)

Set whether or not this FBT represents an EXISTS FBT.

Parameters:

existsBaseTable - Whether or not an EXISTS FBT.

dependencyMap - The dependency map for the EXISTS FBT.

isNotExists - Whether or not for NOT EXISTS, more specifically.

clearDependency

void clearDependency(java.util.List<java.lang.Integer> locations)

Clear the bits from the dependency map when join nodes are flattened

Parameters:

locations - list of bit numbers to be cleared

setTableProperties

void setTableProperties(java.util.Properties tableProperties)

Set the table properties for this table.

Parameters:

tableProperties - The new table properties.

bindNonVTITables

ResultSetNode bindNonVTITables(DataDictionary dataDictionary,
                               FromList fromListParam)
                        throws StandardException

Bind the table in this FromBaseTable. This is where view resolution occurs

Overrides:

bindNonVTITables in class ResultSetNode

Parameters:

dataDictionary - The DataDictionary to use for binding

fromListParam - FromList to use/append to.

Returns:

ResultSetNode The FromTable for the table or resolved view.

Throws:

StandardException - Thrown on error

mapTableAsVTI

private ResultSetNode mapTableAsVTI(TableDescriptor td,
                                    java.lang.String correlationName,
                                    ResultColumnList resultColumns,
                                    java.util.Properties tableProperties,
                                    ContextManager cm)
                             throws StandardException

Return a node that represents invocation of the virtual table for the given table descriptor. The mapping of the table descriptor to a specific VTI class name will occur as part of the "init" phase for the NewInvocationNode that we create here. Currently only handles no argument VTIs corresponding to a subset of the diagnostic tables. (e.g. lock_table). The node returned is a FROM_VTI node with a passed in NEW_INVOCATION_NODE representing the class, with no arguments. Other attributes of the original FROM_TABLE node (such as resultColumns) are passed into the FROM_VTI node.

Throws:

StandardException

getFromTableByName

FromTable getFromTableByName(java.lang.String name,
                             java.lang.String schemaName,
                             boolean exactMatch)
                      throws StandardException

Determine whether or not the specified name is an exposed name in the current query block.

Overrides:

getFromTableByName in class FromTable

Parameters:

name - The specified name to search for as an exposed name.

schemaName - Schema name, if non-null.

exactMatch - Whether or not we need an exact match on specified schema and table names or match on table id.

Returns:

The FromTable, if any, with the exposed name.

Throws:

StandardException - Thrown on error

bindTableDescriptor

private TableDescriptor bindTableDescriptor()
                                     throws StandardException

Bind the table descriptor for this table. If the tableName is a synonym, it will be resolved here. The original table name is retained in origTableName.

Throws:

StandardException - Thrown on error

bindExpressions

void bindExpressions(FromList fromListParam)
              throws StandardException

Bind the expressions in this FromBaseTable. This means binding the sub-expressions, as well as figuring out what the return type is for each expression.

Overrides:

bindExpressions in class ResultSetNode

Parameters:

fromListParam - FromList to use/append to.

Throws:

StandardException - Thrown on error

bindResultColumns

void bindResultColumns(FromList fromListParam)
                throws StandardException

Bind the result columns of this ResultSetNode when there is no base table to bind them to. This is useful for SELECT statements, where the result columns get their types from the expressions that live under them.

Overrides:

bindResultColumns in class ResultSetNode

Parameters:

fromListParam - FromList to use/append to.

Throws:

StandardException - Thrown on error

getMatchingColumn

ResultColumn getMatchingColumn(ColumnReference columnReference)
                        throws StandardException

Try to find a ResultColumn in the table represented by this FromBaseTable that matches the name in the given ColumnReference.

Overrides:

getMatchingColumn in class ResultSetNode

Parameters:

columnReference - The columnReference whose name we're looking for in the given table.

Returns:

A ResultColumn whose expression is the ColumnNode that matches the ColumnReference. Returns null if there is no match.

Throws:

StandardException - Thrown on error

preprocess

ResultSetNode preprocess(int numTables,
                         GroupByList gbl,
                         FromList fromList)
                  throws StandardException

Preprocess a ResultSetNode - this currently means: o Generating a referenced table map for each ResultSetNode. o Putting the WHERE and HAVING clauses in conjunctive normal form (CNF). o Converting the WHERE and HAVING clauses into PredicateLists and classifying them. o Ensuring that a ProjectRestrictNode is generated on top of every FromBaseTable and generated in place of every FromSubquery. o Pushing single table predicates down to the new ProjectRestrictNodes.

Overrides:

preprocess in class ResultSetNode

Parameters:

numTables - The number of tables in the DML Statement

gbl - The group by list, if any

fromList - The from list, if any

Returns:

ResultSetNode at top of preprocessed tree.

Throws:

StandardException - Thrown on error

genProjectRestrict

protected ResultSetNode genProjectRestrict(int numTables)
                                    throws StandardException

Put a ProjectRestrictNode on top of each FromTable in the FromList. ColumnReferences must continue to point to the same ResultColumn, so that ResultColumn must percolate up to the new PRN. However, that ResultColumn will point to a new expression, a VirtualColumnNode, which points to the FromTable and the ResultColumn that is the source for the ColumnReference. (The new PRN will have the original of the ResultColumnList and the ResultColumns from that list. The FromTable will get shallow copies of the ResultColumnList and its ResultColumns. ResultColumn.expression will remain at the FromTable, with the PRN getting a new VirtualColumnNode for each ResultColumn.expression.) We then project out the non-referenced columns. If there are no referenced columns, then the PRN's ResultColumnList will consist of a single ResultColumn whose expression is 1.

Overrides:

genProjectRestrict in class ResultSetNode

Parameters:

numTables - Number of tables in the DML Statement

Returns:

The generated ProjectRestrictNode atop the original FromTable.

Throws:

StandardException - Thrown on error

changeAccessPath

ResultSetNode changeAccessPath()
                        throws StandardException

Description copied from class: ResultSetNode

The optimizer's decision on the access path for a result set may require the generation of extra result sets. For example, if it chooses an index for a FromBaseTable, we need an IndexToBaseRowNode above the FromBaseTable (and the FromBaseTable has to change its column list to match the index. This method in the parent class does not generate any extra result sets. It may be overridden in child classes.

Overrides:

changeAccessPath in class ResultSetNode

Returns:

A ResultSetNode tree modified to do any extra processing for the chosen access path

Throws:

StandardException - Thrown on error

See Also:

ResultSetNode.changeAccessPath()

newResultColumns

private ResultColumnList newResultColumns(ResultColumnList oldColumns,
                                          ConglomerateDescriptor idxCD,
                                          ConglomerateDescriptor heapCD,
                                          boolean cloneRCs)
                                   throws StandardException

Create a new ResultColumnList to reflect the columns in the index described by the given ConglomerateDescriptor. The columns in the new ResultColumnList are based on the columns in the given ResultColumnList, which reflects the columns in the base table.

Parameters:

oldColumns - The original list of columns, which reflects the columns in the base table.

idxCD - The ConglomerateDescriptor, which describes the index that the new ResultColumnList will reflect.

heapCD - The ConglomerateDescriptor for the base heap

cloneRCs - Whether or not to clone the RCs

Returns:

A new ResultColumnList that reflects the columns in the index.

Throws:

StandardException - Thrown on error

generate

void generate(ActivationClassBuilder acb,
              MethodBuilder mb)
       throws StandardException

Generation on a FromBaseTable creates a scan on the optimizer-selected conglomerate.

Overrides:

generate in class QueryTreeNode

Parameters:

acb - The ActivationClassBuilder for the class being built

mb - the execute() method to be built

Throws:

StandardException - Thrown on error

generateResultSet

void generateResultSet(ExpressionClassBuilder acb,
                       MethodBuilder mb)
                throws StandardException

Generation on a FromBaseTable for a SELECT. This logic was separated out so that it could be shared with PREPARE SELECT FILTER.

Overrides:

generateResultSet in class ResultSetNode

Parameters:

acb - The ExpressionClassBuilder for the class being built

mb - The execute() method to be built

Throws:

StandardException - Thrown on error

getFinalCostEstimate

CostEstimate getFinalCostEstimate()

Get the final CostEstimate for this ResultSetNode.

Overrides:

getFinalCostEstimate in class FromTable

Returns:

The final CostEstimate for this ResultSetNode.

pushIndexName

private void pushIndexName(ConglomerateDescriptor cd,
                           MethodBuilder mb)
                    throws StandardException

Throws:

StandardException

generateMaxSpecialResultSet

private void generateMaxSpecialResultSet(ExpressionClassBuilder acb,
                                         MethodBuilder mb)
                                  throws StandardException

Throws:

StandardException

generateDistinctScan

private void generateDistinctScan(ExpressionClassBuilder acb,
                                  MethodBuilder mb)
                           throws StandardException

Throws:

StandardException

generateRefActionDependentTableScan

private void generateRefActionDependentTableScan(ExpressionClassBuilder acb,
                                                 MethodBuilder mb)
                                          throws StandardException

Generation on a FromBaseTable for a referential action dependent table.

Parameters:

acb - The ExpressionClassBuilder for the class being built

mb - The execute() method to be built

Throws:

StandardException - Thrown on error

getScanArguments

private int getScanArguments(ExpressionClassBuilder acb,
                             MethodBuilder mb)
                      throws StandardException

Throws:

StandardException

mapAbsoluteToRelativeColumnPosition

private int mapAbsoluteToRelativeColumnPosition(int absolutePosition)

Convert an absolute to a relative 0-based column position.

Parameters:

absolutePosition - The absolute 0-based column position.

Returns:

The relative 0-based column position.

getExposedName

java.lang.String getExposedName()

Get the exposed name for this table, which is the name that can be used to refer to it in the rest of the query.

Overrides:

getExposedName in class FromTable

Returns:

The exposed name of this table.

getExposedTableName

TableName getExposedTableName()
                       throws StandardException

Get the exposed table name for this table, which is the name that can be used to refer to it in the rest of the query.

Returns:

TableName The exposed name of this table.

Throws:

StandardException - Thrown on error

getTableNameField

TableName getTableNameField()

Return the table name for this table.

Returns:

The table name for this table.

getAllResultColumns

ResultColumnList getAllResultColumns(TableName allTableName)
                              throws StandardException

Return a ResultColumnList with all of the columns in this table. (Used in expanding '*'s.) NOTE: Since this method is for expanding a "*" in the SELECT list, ResultColumn.expression will be a ColumnReference.

Overrides:

getAllResultColumns in class ResultSetNode

Parameters:

allTableName - The qualifier on the "*"

Returns:

ResultColumnList List of result columns from this table.

Throws:

StandardException - Thrown on error

genResultColList

ResultColumnList genResultColList()
                           throws StandardException

Build a ResultColumnList based on all of the columns in this FromBaseTable. NOTE - Since the ResultColumnList generated is for the FromBaseTable, ResultColumn.expression will be a BaseColumnNode.

Returns:

ResultColumnList representing all referenced columns

Throws:

StandardException - Thrown on error

addColsToList

ResultColumnList addColsToList(ResultColumnList inputRcl,
                               FormatableBitSet colsWeWant)
                        throws StandardException

Augment the RCL to include the columns in the FormatableBitSet. If the column is already there, don't add it twice. Column is added as a ResultColumn pointing to a ColumnReference.

Parameters:

inputRcl - The original list

colsWeWant - bit set of cols we want

Returns:

ResultColumnList the rcl

Throws:

StandardException - Thrown on error

getTableName

TableName getTableName()
                throws StandardException

Return a TableName node representing this FromTable.

Overrides:

getTableName in class FromTable

Returns:

a TableName node representing this FromTable.

Throws:

StandardException - Thrown on error

markAsCursorTargetTable

boolean markAsCursorTargetTable()

Mark this ResultSetNode as the target table of an updatable cursor.

Overrides:

markAsCursorTargetTable in class ResultSetNode

Returns:

true if the target table supports positioned updates.

cursorTargetTable

protected boolean cursorTargetTable()

Is this a table that has a FOR UPDATE clause?

Overrides:

cursorTargetTable in class FromTable

Returns:

true/false

markUpdated

void markUpdated(ResultColumnList updateColumns)

Mark as updatable all the columns in the result column list of this FromBaseTable that match the columns in the given update column list.

Parameters:

updateColumns - A ResultColumnList representing the columns to be updated.

referencesTarget

boolean referencesTarget(java.lang.String name,
                         boolean baseTable)
                  throws StandardException

Search to see if a query references the specifed table name.

Overrides:

referencesTarget in class ResultSetNode

Parameters:

name - Table name (String) to search for.

baseTable - Whether or not name is for a base table

Returns:

true if found, else false

Throws:

StandardException - Thrown on error

referencesSessionSchema

public boolean referencesSessionSchema()
                                throws StandardException

Return true if the node references SESSION schema tables (temporary or permanent)

Overrides:

referencesSessionSchema in class QueryTreeNode

Returns:

true if references SESSION schema tables, else false

Throws:

StandardException - Thrown on error

isOneRowResultSet

boolean isOneRowResultSet()
                   throws StandardException

Return whether or not the underlying ResultSet tree will return a single row, at most. This method is intended to be used during generation, after the "truly" best conglomerate has been chosen. This is important for join nodes where we can save the extra next on the right side if we know that it will return at most 1 row.

Overrides:

isOneRowResultSet in class ResultSetNode

Returns:

Whether or not the underlying ResultSet tree will return a single row.

Throws:

StandardException - Thrown on error

isNotExists

boolean isNotExists()

Return whether or not this is actually a EBT for NOT EXISTS.

Overrides:

isNotExists in class ResultSetNode

Returns:

Whether or not the underlying ResultSet tree if for NOT EXISTS.

isOneRowResultSet

boolean isOneRowResultSet(OptimizablePredicateList predList)
                   throws StandardException

Throws:

StandardException

supersetOfUniqueIndex

protected boolean supersetOfUniqueIndex(boolean[] eqCols)
                                 throws StandardException

Determine whether or not the columns marked as true in the passed in array are a superset of any unique index on this table. This is useful for subquery flattening and distinct elimination based on a uniqueness condition.

Parameters:

eqCols - The columns to consider

Returns:

Whether or not the columns marked as true are a superset

Throws:

StandardException

supersetOfUniqueIndex

protected boolean supersetOfUniqueIndex(JBitSet[] tableColMap)
                                 throws StandardException

Determine whether or not the columns marked as true in the passed in join table matrix are a superset of any single column unique index on this table. This is useful for distinct elimination based on a uniqueness condition.

Parameters:

tableColMap - The columns to consider

Returns:

Whether or not the columns marked as true for one at least one table are a superset

Throws:

StandardException

updateTargetLockMode

int updateTargetLockMode()

Get the lock mode for the target table heap of an update or delete statement. It is not always MODE_RECORD. We want the lock on the heap to be consistent with optimizer and eventually system's decision. This is to avoid deadlock (beetle 4318). During update/delete's execution, it will first use this lock mode we return to lock heap to open a RowChanger, then use the lock mode that is the optimizer and system's combined decision to open the actual source conglomerate. We've got to make sure they are consistent. This is the lock chart (for detail reason, see comments below): BEST ACCESS PATH LOCK MODE ON HEAP ---------------------- ----------------------------------------- index row lock heap row lock if READ_COMMITTED, REPEATBLE_READ, or READ_UNCOMMITTED and not specified table lock otherwise, use optimizer decided best acess path's lock mode

Overrides:

updateTargetLockMode in class ResultSetNode

Returns:

The lock mode

See Also:

TransactionController

isOrderedOn

boolean isOrderedOn(ColumnReference[] crs,
                    boolean permuteOrdering,
                    java.util.List<FromBaseTable> fbtHolder)
             throws StandardException

Return whether or not the underlying ResultSet tree is ordered on the specified columns. RESOLVE - This method currently only considers the outermost table of the query block. RESOLVE - We do not currently push method calls down, so we don't worry about whether the equals comparisons can be against a variant method.

Overrides:

isOrderedOn in class ResultSetNode

Parameters:

crs - The specified ColumnReference[]

permuteOrdering - Whether or not the order of the CRs in the array can be permuted

fbtHolder - List that is to be filled with the FromBaseTable

Returns:

Whether the underlying ResultSet tree is ordered on the specified column.

Throws:

StandardException - Thrown on error

disableBulkFetch

void disableBulkFetch()

Turn off bulk fetch

doSpecialMaxScan

void doSpecialMaxScan()

Do a special scan for max.

isPossibleDistinctScan

boolean isPossibleDistinctScan(java.util.Set<BaseColumnNode> distinctColumns)

Is it possible to do a distinct scan on this ResultSet tree. (See SelectNode for the criteria.)

Overrides:

isPossibleDistinctScan in class ResultSetNode

Parameters:

distinctColumns - the set of distinct columns

Returns:

Whether or not it is possible to do a distinct scan on this ResultSet tree.

markForDistinctScan

void markForDistinctScan()

Mark the underlying scan as a distinct scan.

Overrides:

markForDistinctScan in class ResultSetNode

adjustForSortElimination

void adjustForSortElimination()

Description copied from class: ResultSetNode

Notify the underlying result set tree that the optimizer has chosen to "eliminate" a sort. Sort elimination can happen as part of preprocessing (see esp. SelectNode.preprocess(...)) or it can happen if the optimizer chooses an access path that inherently returns the rows in the correct order (also known as a "sort avoidance" plan). In either case we drop the sort and rely on the underlying result set tree to return its rows in the correct order. For most types of ResultSetNodes we automatically get the rows in the correct order if the sort was eliminated. One exception to this rule, though, is the case of an IndexRowToBaseRowNode, for which we have to disable bulk fetching on the underlying base table. Otherwise the index scan could return rows out of order if the base table is updated while the scan is "in progress" (i.e. while the result set is open). In order to account for this (and potentially other, similar issues in the future) this method exists to notify the result set node that it is expected to return rows in the correct order. The result set can then take necessary action to satsify this requirement--such as disabling bulk fetch in the case of IndexRowToBaseRowNode. All of that said, any ResultSetNodes for which we could potentially eliminate sorts should override this method accordingly. So we don't ever expect to get here.

Overrides:

adjustForSortElimination in class ResultSetNode

See Also:

ResultSetNode.adjustForSortElimination()

adjustForSortElimination

void adjustForSortElimination(RequiredRowOrdering rowOrdering)
                       throws StandardException

Description copied from class: ResultSetNode

Same goal as adjustForSortElimination above, but this version takes a RequiredRowOrdering to allow nodes to adjust based on the ORDER BY clause, if needed.

Overrides:

adjustForSortElimination in class ResultSetNode

Throws:

StandardException

See Also:

ResultSetNode.adjustForSortElimination()

isOrdered

private boolean isOrdered(ColumnReference[] crs,
                          ConglomerateDescriptor cd)
                   throws StandardException

Return whether or not this index is ordered on a permutation of the specified columns.

Parameters:

crs - The specified ColumnReference[]

cd - The ConglomerateDescriptor for the chosen index.

Returns:

Whether or not this index is ordered exactly on the specified columns.

Throws:

StandardException - Thrown on error

isStrictlyOrdered

private boolean isStrictlyOrdered(ColumnReference[] crs,
                                  ConglomerateDescriptor cd)
                           throws StandardException

Return whether or not this index is ordered on a permutation of the specified columns.

Parameters:

crs - The specified ColumnReference[]

cd - The ConglomerateDescriptor for the chosen index.

Returns:

Whether or not this index is ordered exactly on the specified columns.

Throws:

StandardException - Thrown on error

isOneRowResultSet

private boolean isOneRowResultSet(ConglomerateDescriptor cd,
                                  OptimizablePredicateList predList)
                           throws StandardException

Is this a one-row result set with the given conglomerate descriptor?

Throws:

StandardException

getDefaultBulkFetch

private int getDefaultBulkFetch()
                         throws StandardException

Throws:

StandardException

getUserSpecifiedIndexName

private java.lang.String getUserSpecifiedIndexName()

getStoreCostController

private StoreCostController getStoreCostController(ConglomerateDescriptor cd)
                                            throws StandardException

Throws:

StandardException

getBaseCostController

private StoreCostController getBaseCostController()
                                           throws StandardException

Throws:

StandardException

baseRowCount

private long baseRowCount()
                   throws StandardException

Throws:

StandardException

getRowTemplate

private DataValueDescriptor[] getRowTemplate(ConglomerateDescriptor cd,
                                             StoreCostController scc)
                                      throws StandardException

Throws:

StandardException

getFirstConglom

private ConglomerateDescriptor getFirstConglom()
                                        throws StandardException

Throws:

StandardException

getNextConglom

private ConglomerateDescriptor getNextConglom(ConglomerateDescriptor currCD)

getConglomDescs

private void getConglomDescs()
                      throws StandardException

Throws:

StandardException

setRefActionInfo

void setRefActionInfo(long fkIndexConglomId,
                      int[] fkColArray,
                      java.lang.String parentResultSetId,
                      boolean dependentScan)

set the Information gathered from the parent table that is required to perform a referential action on dependent table.

Overrides:

setRefActionInfo in class QueryTreeNode

acceptChildren

void acceptChildren(Visitor v)
             throws StandardException

Accept the visitor for all visitable children of this node.

Overrides:

acceptChildren in class FromTable

Parameters:

v - the visitor

Throws:

StandardException - on error

qualifiesForStatisticsUpdateCheck

private boolean qualifiesForStatisticsUpdateCheck(TableDescriptor td)
                                           throws StandardException

Tells if the given table qualifies for a statistics update check in the current configuration.

Parameters:

td - the table to check

Returns:

true if qualified, false if not

Throws:

StandardException