Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> sql >> [ compile overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---

org.apache.derby.impl.sql.compile
Class OptimizerImpl  

java.lang.Object
  org.apache.derby.impl.sql.compile.OptimizerImpl

All Implemented Interfaces:

org.apache.derby.iapi.sql.compile.Optimizer

Direct Known Subclasses:

Level2OptimizerImpl

---

public class OptimizerImpl

extends java.lang.Object

implements org.apache.derby.iapi.sql.compile.Optimizer

This will be the Level 1 Optimizer. RESOLVE - it's a level 0 optimizer right now. Current State: o No costing services o We can only cost a derived table with a join once. Optimizer uses OptimizableList to keep track of the best join order as it builds it. For each available slot in the join order, we cost all of the Optimizables from that slot til the end of the OptimizableList. Later, we will choose the best Optimizable for that slot and reorder the list accordingly. In order to do this, we probably need to move the temporary pushing and pulling of join clauses into Optimizer, since the logic will be different for other implementations. (Of course, we're not pushing and pulling join clauses between permutations yet.)

---

Field Summary
protected  org.apache.derby.iapi.util.JBitSet	assignedTableMap
protected  CostEstimateImpl	bestCost
protected  int[]	bestJoinOrder
private  org.apache.derby.iapi.sql.compile.RowOrdering	bestRowOrdering
private  boolean	conglomerate_OneRowResultSet
protected  CostEstimateImpl	currentCost
private  org.apache.derby.iapi.sql.compile.RowOrdering	currentRowOrdering
protected  CostEstimateImpl	currentSortAvoidanceCost
protected  long	currentTime
(package private)  org.apache.derby.iapi.sql.dictionary.DataDictionary	dDictionary
(package private)  boolean	desiredJoinOrderFound
private  int[]	firstLookOrder
private  boolean	foundABestPlan
protected  int	joinPosition
private  org.apache.derby.iapi.sql.compile.JoinStrategy[]	joinStrategies
private static int	JUMPING
protected  int	maxMemoryPerTable
private static int	NO_JUMP
(package private)  org.apache.derby.iapi.util.JBitSet	nonCorrelatedTableMap
private  boolean	noTimeout
(package private)  int	numOptimizables
(package private)  int	numTablesInQuery
protected  org.apache.derby.iapi.sql.compile.OptimizableList	optimizableList
protected  boolean	optimizerTrace
protected  boolean	optimizerTraceHtml
private  CostEstimateImpl	outermostCostEstimate
private  int	permuteState
(package private)  org.apache.derby.iapi.sql.compile.OptimizablePredicateList	predicateList
protected  int[]	proposedJoinOrder
private static int	READY_TO_JUMP
protected  org.apache.derby.iapi.sql.compile.RequiredRowOrdering	requiredRowOrdering
private  boolean	ruleBasedOptimization
protected  org.apache.derby.iapi.sql.compile.CostEstimate	sortCost
private  int	tableLockThreshold
protected  boolean	timeExceeded
protected  long	timeOptimizationStarted
private  boolean	useStatistics
private static int	WALK_HIGH
private static int	WALK_LOW

 

Fields inherited from interface org.apache.derby.iapi.sql.compile.Optimizer

ADDING_UNORDERED_OPTIMIZABLE, CALLING_NEXT_ACCESS_PATH, CALLING_ON_JOIN_NODE, CHANGING_ACCESS_PATH_FOR_TABLE, CHEAPEST_PLAN_SO_FAR, COMPLETE_JOIN_ORDER, COMPOSITE_SEL_FROM_STATS, CONSIDERING_CONGLOMERATE, CONSIDERING_JOIN_ORDER, CONSIDERING_JOIN_STRATEGY, COST_INCLUDING_COMPOSITE_SEL_FROM_STATS, COST_INCLUDING_EXTRA_1ST_COL_SELECTIVITY, COST_INCLUDING_EXTRA_NONQUALIFIER_SELECTIVITY, COST_INCLUDING_EXTRA_QUALIFIER_SELECTIVITY, COST_INCLUDING_EXTRA_START_STOP, COST_INCLUDING_STATS_FOR_INDEX, COST_OF_CHEAPEST_PLAN_SO_FAR, COST_OF_CONGLOMERATE_SCAN1, COST_OF_CONGLOMERATE_SCAN2, COST_OF_CONGLOMERATE_SCAN3, COST_OF_CONGLOMERATE_SCAN4, COST_OF_CONGLOMERATE_SCAN5, COST_OF_CONGLOMERATE_SCAN6, COST_OF_CONGLOMERATE_SCAN7, COST_OF_N_SCANS, COST_OF_NONCOVERING_INDEX, COST_OF_SORTING, CURRENT_PLAN_IS_SA_PLAN, ESTIMATING_COST_OF_CONGLOMERATE, HJ_HASH_KEY_COLUMNS, HJ_SKIP_NO_JOIN_COLUMNS, HJ_SKIP_NOT_MATERIALIZABLE, ILLEGAL_USER_JOIN_ORDER, JOIN_ORDER_OPTIMIZATION, LOOKING_FOR_SPECIFIED_INDEX, MATCH_SINGLE_ROW_COST, MAX_MEMORY_PER_TABLE, MODIFYING_ACCESS_PATHS, MODULE, NO_BEST_PLAN, NO_MORE_CONGLOMERATES, NO_TABLES, NO_TIMEOUT, NON_COVERING_INDEX_COST, NORMAL_PLAN, PLAN_TYPE, REMEMBERING_BEST_ACCESS_PATH, REMEMBERING_BEST_ACCESS_PATH_SUBSTRING, REMEMBERING_BEST_JOIN_ORDER, REMEMBERING_BEST_SORT_AVOIDANCE_ACCESS_PATH_SUBSTRING, REMEMBERING_BEST_UNKNOWN_ACCESS_PATH_SUBSTRING, REMEMBERING_JOIN_STRATEGY, ROW_LOCK_ALL_CONSTANT_START_STOP, ROW_LOCK_UNDER_THRESHOLD, RULE_BASED_OPTIMIZATION, SCANNING_HEAP_FULL_MATCH_ON_UNIQUE_KEY, SHORT_CIRCUITING, SKIPPING_DUE_TO_EXCESS_MEMORY, SKIPPING_JOIN_ORDER, SORT_AVOIDANCE_PLAN, SORT_NEEDED_FOR_ORDERING, STARTED, TABLE_LOCK_NO_START_STOP, TABLE_LOCK_OVER_THRESHOLD, TIME_EXCEEDED, TOTAL_COST_NON_SA_PLAN, TOTAL_COST_SA_PLAN, TOTAL_COST_WITH_SORTING, USE_STATISTICS, USER_JOIN_ORDER_OPTIMIZED

 

Constructor Summary

protected

OptimizerImpl(org.apache.derby.iapi.sql.compile.OptimizableList optimizableList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predicateList, org.apache.derby.iapi.sql.dictionary.DataDictionary dDictionary, boolean ruleBasedOptimization, boolean noTimeout, boolean useStatistics, int maxMemoryPerTable, org.apache.derby.iapi.sql.compile.JoinStrategy[] joinStrategies, int tableLockThreshold, org.apache.derby.iapi.sql.compile.RequiredRowOrdering requiredRowOrdering, int numTablesInQuery)

 

Method Summary
void	considerCost(org.apache.derby.iapi.sql.compile.Optimizable optimizable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.CostEstimate estimatedCost, org.apache.derby.iapi.sql.compile.CostEstimate outerCost)           This is the version of costOptimizable for non-base-tables.
private  void	costBasedCostOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable, org.apache.derby.iapi.sql.dictionary.TableDescriptor td, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.CostEstimate outerCost)           This method decides whether the given conglomerate descriptor is cheapest based on cost, rather than based on rules.
void	costOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable, org.apache.derby.iapi.sql.dictionary.TableDescriptor td, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.CostEstimate outerCost)           Cost the current Optimizable with the specified OPL.
void	costPermutation()           Cost the current permutation.
private  org.apache.derby.iapi.sql.compile.CostEstimate	estimateTotalCost(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.CostEstimate outerCost, org.apache.derby.iapi.sql.compile.Optimizable optimizable)           Estimate the total cost of doing a join with the given optimizable.
org.apache.derby.iapi.sql.dictionary.DataDictionary	getDataDictionary()           Return the DataDictionary that the Optimizer is using.
org.apache.derby.iapi.sql.compile.JoinStrategy	getJoinStrategy(int whichStrategy)           Gets a join strategy by number (zero-based).
org.apache.derby.iapi.sql.compile.JoinStrategy	getJoinStrategy(java.lang.String whichStrategy)           Gets a join strategy by name.
int	getLevel()           Get the level of this optimizer.
int	getMaxMemoryPerTable()
CostEstimateImpl	getNewCostEstimate(double theCost, double theRowCount, double theSingleScanRowCount)
boolean	getNextDecoratedPermutation()           Iterate through the "decorated permutations", returning false when they are exhausted.
boolean	getNextPermutation()           Iterate through the permutations, returning false when the permutations are exhausted.
int	getNumberOfJoinStrategies()           Get the number of join strategies supported by this optimizer.
org.apache.derby.iapi.sql.compile.CostEstimate	getOptimizedCost()           Get the estimated cost of the optimized query
private  boolean	isPushable(org.apache.derby.iapi.sql.compile.OptimizablePredicate pred)
void	modifyAccessPaths()           Modify the access path for each Optimizable, as necessary.
org.apache.derby.iapi.sql.compile.CostEstimate	newCostEstimate()           Get a new CostEstimate object
(package private)  void	pushPredicates(org.apache.derby.iapi.sql.compile.Optimizable curTable, org.apache.derby.iapi.util.JBitSet outerTables)
private  void	rememberBestCost(org.apache.derby.iapi.sql.compile.CostEstimate currentCost, int planType)           Is the cost of this join order lower than the best one we've found so far? If so, remember it.
private  void	rewindJoinOrder()
private  void	ruleBasedCostOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable, org.apache.derby.iapi.sql.dictionary.TableDescriptor td, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.CostEstimate outerCost)           This method decides whether the given conglomerate descriptor is cheapest based on rules, rather than based on cost estimates.
void	setOuterRows(double outerRows)           Set the estimated number of outer rows - good for optimizing nested optimizables like subqueries and join nodes.
int	tableLockThreshold()           Get the maximum number of estimated rows touched in a table before we decide to open the table with table locking (as opposed to row locking.
void	trace(int traceFlag, int intParam1, int intParam2, double doubleParam, java.lang.Object objectParam1)           Optimizer trace.
double	uniqueJoinWithOuterTable(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)           Tells whether any of the tables outer to the current one has a uniqueness condition on the given predicate list, and if so, how many times each unique key can be seen by the current table.
boolean	useStatistics()           If statistics should be considered by the optimizer while optimizing a query.

 

Methods inherited from class java.lang.Object

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

 

Field Detail

dDictionary

org.apache.derby.iapi.sql.dictionary.DataDictionary dDictionary

---

numTablesInQuery

int numTablesInQuery

---

numOptimizables

int numOptimizables

---

assignedTableMap

protected org.apache.derby.iapi.util.JBitSet assignedTableMap

---

optimizableList

protected org.apache.derby.iapi.sql.compile.OptimizableList optimizableList

---

predicateList

org.apache.derby.iapi.sql.compile.OptimizablePredicateList predicateList

---

nonCorrelatedTableMap

org.apache.derby.iapi.util.JBitSet nonCorrelatedTableMap

---

proposedJoinOrder

protected int[] proposedJoinOrder

---

bestJoinOrder

protected int[] bestJoinOrder

---

joinPosition

protected int joinPosition

---

desiredJoinOrderFound

boolean desiredJoinOrderFound

---

NO_JUMP

private static final int NO_JUMP

See Also:

Constant Field Values

---

READY_TO_JUMP

private static final int READY_TO_JUMP

See Also:

Constant Field Values

---

JUMPING

private static final int JUMPING

See Also:

Constant Field Values

---

WALK_HIGH

private static final int WALK_HIGH

See Also:

Constant Field Values

---

WALK_LOW

private static final int WALK_LOW

See Also:

Constant Field Values

---

permuteState

private int permuteState

---

firstLookOrder

private int[] firstLookOrder

---

ruleBasedOptimization

private boolean ruleBasedOptimization

---

outermostCostEstimate

private CostEstimateImpl outermostCostEstimate

---

currentCost

protected CostEstimateImpl currentCost

---

currentSortAvoidanceCost

protected CostEstimateImpl currentSortAvoidanceCost

---

bestCost

protected CostEstimateImpl bestCost

---

timeOptimizationStarted

protected long timeOptimizationStarted

---

currentTime

protected long currentTime

---

timeExceeded

protected boolean timeExceeded

---

noTimeout

private boolean noTimeout

---

useStatistics

private boolean useStatistics

---

tableLockThreshold

private int tableLockThreshold

---

joinStrategies

private org.apache.derby.iapi.sql.compile.JoinStrategy[] joinStrategies

---

requiredRowOrdering

protected org.apache.derby.iapi.sql.compile.RequiredRowOrdering requiredRowOrdering

---

foundABestPlan

private boolean foundABestPlan

---

sortCost

protected org.apache.derby.iapi.sql.compile.CostEstimate sortCost

---

currentRowOrdering

private org.apache.derby.iapi.sql.compile.RowOrdering currentRowOrdering

---

bestRowOrdering

private org.apache.derby.iapi.sql.compile.RowOrdering bestRowOrdering

---

conglomerate_OneRowResultSet

private boolean conglomerate_OneRowResultSet

---

optimizerTrace

protected boolean optimizerTrace

---

optimizerTraceHtml

protected boolean optimizerTraceHtml

---

maxMemoryPerTable

protected int maxMemoryPerTable

Constructor Detail

OptimizerImpl

protected OptimizerImpl(org.apache.derby.iapi.sql.compile.OptimizableList optimizableList,
                        org.apache.derby.iapi.sql.compile.OptimizablePredicateList predicateList,
                        org.apache.derby.iapi.sql.dictionary.DataDictionary dDictionary,
                        boolean ruleBasedOptimization,
                        boolean noTimeout,
                        boolean useStatistics,
                        int maxMemoryPerTable,
                        org.apache.derby.iapi.sql.compile.JoinStrategy[] joinStrategies,
                        int tableLockThreshold,
                        org.apache.derby.iapi.sql.compile.RequiredRowOrdering requiredRowOrdering,
                        int numTablesInQuery)
                 throws org.apache.derby.iapi.error.StandardException

Method Detail

getMaxMemoryPerTable

public int getMaxMemoryPerTable()

Specified by:

getMaxMemoryPerTable in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getNextPermutation

public boolean getNextPermutation()
                           throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Iterate through the permutations, returning false when the permutations are exhausted. NOTE - Implementers are responsible for hiding tree pruning of permutations behind this method call.

Specified by:

getNextPermutation in interface org.apache.derby.iapi.sql.compile.Optimizer

---

rewindJoinOrder

private void rewindJoinOrder()
                      throws org.apache.derby.iapi.error.StandardException

---

pushPredicates

void pushPredicates(org.apache.derby.iapi.sql.compile.Optimizable curTable,
                    org.apache.derby.iapi.util.JBitSet outerTables)
              throws org.apache.derby.iapi.error.StandardException

---

getNextDecoratedPermutation

public boolean getNextDecoratedPermutation()
                                    throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Iterate through the "decorated permutations", returning false when they are exhausted. NOTE - Implementers are responsible for hiding tree pruning of access methods behind this method call.

Specified by:

getNextDecoratedPermutation in interface org.apache.derby.iapi.sql.compile.Optimizer

---

rememberBestCost

private void rememberBestCost(org.apache.derby.iapi.sql.compile.CostEstimate currentCost,
                              int planType)
                       throws org.apache.derby.iapi.error.StandardException

Is the cost of this join order lower than the best one we've found so far? If so, remember it. NOTE: If the user has specified a join order, it will be the only join order the optimizer considers, so it is OK to use costing to decide that it is the "best" join order.

---

costPermutation

public void costPermutation()
                     throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Cost the current permutation. Caller is responsible for pushing all predicates which can be evaluated prior to costing.

Specified by:

costPermutation in interface org.apache.derby.iapi.sql.compile.Optimizer

---

costOptimizable

public void costOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable,
                            org.apache.derby.iapi.sql.dictionary.TableDescriptor td,
                            org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                            org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                            org.apache.derby.iapi.sql.compile.CostEstimate outerCost)
                     throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Cost the current Optimizable with the specified OPL. Caller is responsible for pushing all predicates which can be evaluated prior to costing.

Specified by:

costOptimizable in interface org.apache.derby.iapi.sql.compile.Optimizer

---

ruleBasedCostOptimizable

private void ruleBasedCostOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable,
                                      org.apache.derby.iapi.sql.dictionary.TableDescriptor td,
                                      org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                                      org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                                      org.apache.derby.iapi.sql.compile.CostEstimate outerCost)
                               throws org.apache.derby.iapi.error.StandardException

This method decides whether the given conglomerate descriptor is cheapest based on rules, rather than based on cost estimates. The rules are: Covering matching indexes are preferred above all Non-covering matching indexes are next in order of preference Covering non-matching indexes are next in order of preference Heap scans are next in order of preference Non-covering, non-matching indexes are last in order of preference. In the current language architecture, there will always be a heap, so a non-covering, non-matching index scan will never be chosen. However, the optimizer may see a non-covering, non-matching index first, in which case it will choose it temporarily as the best conglomerate seen so far. NOTE: This method sets the cost in the optimizable, even though it doesn't use the cost to determine which access path to choose. There are two reasons for this: the cost might be needed to determine join order, and the cost information is copied to the query plan.

---

costBasedCostOptimizable

private void costBasedCostOptimizable(org.apache.derby.iapi.sql.compile.Optimizable optimizable,
                                      org.apache.derby.iapi.sql.dictionary.TableDescriptor td,
                                      org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                                      org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                                      org.apache.derby.iapi.sql.compile.CostEstimate outerCost)
                               throws org.apache.derby.iapi.error.StandardException

This method decides whether the given conglomerate descriptor is cheapest based on cost, rather than based on rules. It compares the cost of using the given ConglomerateDescriptor with the cost of using the best ConglomerateDescriptor so far.

---

considerCost

public void considerCost(org.apache.derby.iapi.sql.compile.Optimizable optimizable,
                         org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                         org.apache.derby.iapi.sql.compile.CostEstimate estimatedCost,
                         org.apache.derby.iapi.sql.compile.CostEstimate outerCost)
                  throws org.apache.derby.iapi.error.StandardException

This is the version of costOptimizable for non-base-tables.

Specified by:

considerCost in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getDataDictionary

public org.apache.derby.iapi.sql.dictionary.DataDictionary getDataDictionary()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Return the DataDictionary that the Optimizer is using. This is useful when an Optimizable needs to call optimize() on a child ResultSetNode.

Specified by:

getDataDictionary in interface org.apache.derby.iapi.sql.compile.Optimizer

---

modifyAccessPaths

public void modifyAccessPaths()
                       throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Modify the access path for each Optimizable, as necessary. This includes things like adding result sets to translate from index rows to base rows.

Specified by:

modifyAccessPaths in interface org.apache.derby.iapi.sql.compile.Optimizer

---

newCostEstimate

public org.apache.derby.iapi.sql.compile.CostEstimate newCostEstimate()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Get a new CostEstimate object

Specified by:

newCostEstimate in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getOptimizedCost

public org.apache.derby.iapi.sql.compile.CostEstimate getOptimizedCost()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Get the estimated cost of the optimized query

Specified by:

getOptimizedCost in interface org.apache.derby.iapi.sql.compile.Optimizer

---

setOuterRows

public void setOuterRows(double outerRows)

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Set the estimated number of outer rows - good for optimizing nested optimizables like subqueries and join nodes.

Specified by:

setOuterRows in interface org.apache.derby.iapi.sql.compile.Optimizer

---

tableLockThreshold

public int tableLockThreshold()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Get the maximum number of estimated rows touched in a table before we decide to open the table with table locking (as opposed to row locking.

Specified by:

tableLockThreshold in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getNumberOfJoinStrategies

public int getNumberOfJoinStrategies()

Get the number of join strategies supported by this optimizer.

Specified by:

getNumberOfJoinStrategies in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getJoinStrategy

public org.apache.derby.iapi.sql.compile.JoinStrategy getJoinStrategy(int whichStrategy)

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Gets a join strategy by number (zero-based).

Specified by:

getJoinStrategy in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getJoinStrategy

public org.apache.derby.iapi.sql.compile.JoinStrategy getJoinStrategy(java.lang.String whichStrategy)

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Gets a join strategy by name. Returns null if not found. The look-up is case-insensitive.

Specified by:

getJoinStrategy in interface org.apache.derby.iapi.sql.compile.Optimizer

---

uniqueJoinWithOuterTable

public double uniqueJoinWithOuterTable(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)
                                throws org.apache.derby.iapi.error.StandardException

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Tells whether any of the tables outer to the current one has a uniqueness condition on the given predicate list, and if so, how many times each unique key can be seen by the current table.

Specified by:

uniqueJoinWithOuterTable in interface org.apache.derby.iapi.sql.compile.Optimizer

---

isPushable

private boolean isPushable(org.apache.derby.iapi.sql.compile.OptimizablePredicate pred)

---

estimateTotalCost

private org.apache.derby.iapi.sql.compile.CostEstimate estimateTotalCost(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                                                                         org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                                                                         org.apache.derby.iapi.sql.compile.CostEstimate outerCost,
                                                                         org.apache.derby.iapi.sql.compile.Optimizable optimizable)
                                                                  throws org.apache.derby.iapi.error.StandardException

Estimate the total cost of doing a join with the given optimizable.

---

getLevel

public int getLevel()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Get the level of this optimizer.

Specified by:

getLevel in interface org.apache.derby.iapi.sql.compile.Optimizer

---

getNewCostEstimate

public CostEstimateImpl getNewCostEstimate(double theCost,
                                           double theRowCount,
                                           double theSingleScanRowCount)

---

trace

public void trace(int traceFlag,
                  int intParam1,
                  int intParam2,
                  double doubleParam,
                  java.lang.Object objectParam1)

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

Optimizer trace.

Specified by:

trace in interface org.apache.derby.iapi.sql.compile.Optimizer

---

useStatistics

public boolean useStatistics()

Description copied from interface: org.apache.derby.iapi.sql.compile.Optimizer

If statistics should be considered by the optimizer while optimizing a query. The user may disable the use of statistics by setting the property derby.optimizer.useStatistics or by using the property useStatistics in a query.

Specified by:

useStatistics in interface org.apache.derby.iapi.sql.compile.Optimizer

---

Overview  Package   Class  Use  Deprecated  Index
Home >> All >> org >> apache >> derby >> impl >> sql >> [ compile overview ]	PREV CLASS  NEXT CLASS
SUMMARY:  JAVADOC |  SOURCE |  DOWNLOAD | NESTED | FIELD | CONSTR | METHOD	DETAIL: FIELD | CONSTR | METHOD

---