HashJoinStrategy

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

java.lang.Object
  org.apache.derby.impl.sql.compile.BaseJoinStrategy
      org.apache.derby.impl.sql.compile.HashJoinStrategy

All Implemented Interfaces:: org.apache.derby.iapi.sql.compile.JoinStrategy

public class HashJoinStrategy
extends BaseJoinStrategy

Constructor Summary

HashJoinStrategy()


Method Summary

void divideUpPredicateLists(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList originalRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList requalificationRestrictionList, org.apache.derby.iapi.sql.dictionary.DataDictionary dd)
          Divide up the predicates into different lists for different phases of the operation.

boolean doesMaterialization()
          Is materialization built in to the join strategy?

void estimateCost(org.apache.derby.iapi.sql.compile.Optimizable innerTable, 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.Optimizer optimizer, org.apache.derby.iapi.sql.compile.CostEstimate costEstimate)
          Get the estimated cost for the join.

boolean feasible(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.Optimizer optimizer)
          Is this join strategy feasible under the circumstances?

private int[] findHashKeyColumns(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)
          Find the hash key columns, if any, to use with this join.

org.apache.derby.iapi.sql.compile.OptimizablePredicateList getBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates, org.apache.derby.iapi.sql.compile.Optimizable innerTable)
          Get the base predicates for this join strategy.

java.lang.String getName()
          Get the name of this join strategy

int getScanArgs(org.apache.derby.iapi.store.access.TransactionController tc, org.apache.derby.iapi.services.compiler.MethodBuilder mb, org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList, org.apache.derby.iapi.sql.compile.ExpressionClassBuilderInterface acbi, int bulkFetch, org.apache.derby.iapi.services.compiler.MethodBuilder resultRowAllocator, int colRefItem, int indexColItem, int lockMode, boolean tableLocked, int isolationLevel, int maxMemoryPerTable)
          Get the appropriate arguments to the scan for this type of join.

java.lang.String halfOuterJoinResultSetMethodName()
          Get the name of the join result set method for the half outerjoin

boolean ignoreBulkFetch()
          Should we just ignore bulk fetch with this join strategy?

boolean isHashJoin()
          Is this a form of hash join?

java.lang.String joinResultSetMethodName()
          Get the name of the join result set method for the join

int maxCapacity(int userSpecifiedCapacity, int maxMemoryPerTable, double perRowUsage)


boolean multiplyBaseCostByOuterRows()
          Returns true if the base cost of scanning the conglomerate should be multiplied by the number of outer rows.

double nonBasePredicateSelectivity(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)
          Get the extra selectivity of the non-base predicates (those that were left in the predicate list by getBasePredicates() that are not applied to the scan of the base conglomerate.

void putBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates)
          Put back and base predicates that were removed from the list by getBasePredicates (see above).

java.lang.String resultSetMethodName(boolean bulkFetch)
          Get the name of the result set method for base table scans

int scanCostType()
          Get the costing type, for use with StoreCostController.getScanCost

java.lang.String toString()
          Convert this Object to a human-readable String.

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

bulkFetchOK, fillInScanArgs1, fillInScanArgs2, validForOutermostTable

Methods inherited from class java.lang.Object

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

Constructor Detail

HashJoinStrategy

public HashJoinStrategy()

Method Detail

feasible

public boolean feasible(org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                        org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                        org.apache.derby.iapi.sql.compile.Optimizer optimizer)
                 throws org.apache.derby.iapi.error.StandardException

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

Is this join strategy feasible under the circumstances?

ignoreBulkFetch

public boolean ignoreBulkFetch()

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

Should we just ignore bulk fetch with this join strategy?

Specified by:: ignoreBulkFetch in interface org.apache.derby.iapi.sql.compile.JoinStrategy
Overrides:: ignoreBulkFetch in class BaseJoinStrategy

multiplyBaseCostByOuterRows

public boolean multiplyBaseCostByOuterRows()

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

Returns true if the base cost of scanning the conglomerate should be multiplied by the number of outer rows.

getBasePredicates

public org.apache.derby.iapi.sql.compile.OptimizablePredicateList getBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                                                                                    org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates,
                                                                                    org.apache.derby.iapi.sql.compile.Optimizable innerTable)
                                                                             throws org.apache.derby.iapi.error.StandardException

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

Get the base predicates for this join strategy. The base predicates are the ones that can be used while scanning the table. For some join strategies (for example, nested loop), all predicates are base predicates. For other join strategies (for example, hash join), the base predicates are those that involve comparisons with constant expressions. Also, order the base predicates according to the order in the proposed conglomerate descriptor for the inner table.

nonBasePredicateSelectivity

public double nonBasePredicateSelectivity(org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                                          org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)

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

Get the extra selectivity of the non-base predicates (those that were left in the predicate list by getBasePredicates() that are not applied to the scan of the base conglomerate. NOTE: For some types of join strategy, it may not remove any predicates from the original predicate list. The join strategy is expected to know when it does this, and to return 1.0 as the extra selectivity in these cases.

putBasePredicates

public void putBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList,
                              org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates)
                       throws org.apache.derby.iapi.error.StandardException

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

Put back and base predicates that were removed from the list by getBasePredicates (see above). NOTE: Those join strategies that treat all predicates as base predicates may treat the get and put methods as no-ops.

estimateCost

public void estimateCost(org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                         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.Optimizer optimizer,
                         org.apache.derby.iapi.sql.compile.CostEstimate costEstimate)

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

Get the estimated cost for the join.

maxCapacity

public int maxCapacity(int userSpecifiedCapacity,
                       int maxMemoryPerTable,
                       double perRowUsage)

getName

public java.lang.String getName()

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

Get the name of this join strategy

scanCostType

public int scanCostType()

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

Get the costing type, for use with StoreCostController.getScanCost

resultSetMethodName

public java.lang.String resultSetMethodName(boolean bulkFetch)

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

Get the name of the result set method for base table scans

joinResultSetMethodName

public java.lang.String joinResultSetMethodName()

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

Get the name of the join result set method for the join

halfOuterJoinResultSetMethodName

public java.lang.String halfOuterJoinResultSetMethodName()

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

Get the name of the join result set method for the half outerjoin

getScanArgs

public int getScanArgs(org.apache.derby.iapi.store.access.TransactionController tc,
                       org.apache.derby.iapi.services.compiler.MethodBuilder mb,
                       org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                       org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList,
                       org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList,
                       org.apache.derby.iapi.sql.compile.ExpressionClassBuilderInterface acbi,
                       int bulkFetch,
                       org.apache.derby.iapi.services.compiler.MethodBuilder resultRowAllocator,
                       int colRefItem,
                       int indexColItem,
                       int lockMode,
                       boolean tableLocked,
                       int isolationLevel,
                       int maxMemoryPerTable)
                throws org.apache.derby.iapi.error.StandardException

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

Get the appropriate arguments to the scan for this type of join.

divideUpPredicateLists

public void divideUpPredicateLists(org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                                   org.apache.derby.iapi.sql.compile.OptimizablePredicateList originalRestrictionList,
                                   org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList,
                                   org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList,
                                   org.apache.derby.iapi.sql.compile.OptimizablePredicateList requalificationRestrictionList,
                                   org.apache.derby.iapi.sql.dictionary.DataDictionary dd)
                            throws org.apache.derby.iapi.error.StandardException

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

Divide up the predicates into different lists for different phases of the operation. When this method is called, all of the predicates will be in restrictionList. The effect of this method is to remove all of the predicates from restrictionList except those that will be pushed down to the store as start/stop predicates or Qualifiers. The remaining predicates will be put into nonBaseTableRestrictionList. All predicate lists will be ordered as necessary for use with the conglomerate. Some operations (like hash join) materialize results, and so require requalification of rows when doing a non-covering index scan. The predicates to use for requalification are copied into baseTableRestrictionList.

isHashJoin

public boolean isHashJoin()

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

Is this a form of hash join?

Specified by:: isHashJoin in interface org.apache.derby.iapi.sql.compile.JoinStrategy
Overrides:: isHashJoin in class BaseJoinStrategy

doesMaterialization

public boolean doesMaterialization()

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

Is materialization built in to the join strategy?

findHashKeyColumns

private int[] findHashKeyColumns(org.apache.derby.iapi.sql.compile.Optimizable innerTable,
                                 org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd,
                                 org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)
                          throws org.apache.derby.iapi.error.StandardException

Find the hash key columns, if any, to use with this join.

toString

public java.lang.String toString()

Description copied from class: java.lang.Object

Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() 55 and such.

It is typical, but not required, to ensure that this method never completes abruptly with a java.lang.RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overview

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Class

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Deprecated

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Home >> All >> org >> apache >> derby >> impl >> sql >> [ compile overview ]

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Method Summary
`void`	`divideUpPredicateLists(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList originalRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList requalificationRestrictionList, org.apache.derby.iapi.sql.dictionary.DataDictionary dd)` Divide up the predicates into different lists for different phases of the operation.
`boolean`	`doesMaterialization()` Is materialization built in to the join strategy?
`void`	`estimateCost(org.apache.derby.iapi.sql.compile.Optimizable innerTable, 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.Optimizer optimizer, org.apache.derby.iapi.sql.compile.CostEstimate costEstimate)` Get the estimated cost for the join.
`boolean`	`feasible(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.Optimizer optimizer)` Is this join strategy feasible under the circumstances?
`private int[]`	`findHashKeyColumns(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor cd, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)` Find the hash key columns, if any, to use with this join.
`org.apache.derby.iapi.sql.compile.OptimizablePredicateList`	`getBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates, org.apache.derby.iapi.sql.compile.Optimizable innerTable)` Get the base predicates for this join strategy.
`java.lang.String`	`getName()` Get the name of this join strategy
`int`	getScanArgs(org.apache.derby.iapi.store.access.TransactionController tc, org.apache.derby.iapi.services.compiler.MethodBuilder mb, org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList storeRestrictionList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList nonStoreRestrictionList, org.apache.derby.iapi.sql.compile.ExpressionClassBuilderInterface acbi, int bulkFetch, org.apache.derby.iapi.services.compiler.MethodBuilder resultRowAllocator, int colRefItem, int indexColItem, int lockMode, boolean tableLocked, int isolationLevel, int maxMemoryPerTable) Get the appropriate arguments to the scan for this type of join.
`java.lang.String`	`halfOuterJoinResultSetMethodName()` Get the name of the join result set method for the half outerjoin
`boolean`	`ignoreBulkFetch()` Should we just ignore bulk fetch with this join strategy?
`boolean`	`isHashJoin()` Is this a form of hash join?
`java.lang.String`	`joinResultSetMethodName()` Get the name of the join result set method for the join
`int`	`maxCapacity(int userSpecifiedCapacity, int maxMemoryPerTable, double perRowUsage)`
`boolean`	`multiplyBaseCostByOuterRows()` Returns true if the base cost of scanning the conglomerate should be multiplied by the number of outer rows.
`double`	`nonBasePredicateSelectivity(org.apache.derby.iapi.sql.compile.Optimizable innerTable, org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList)` Get the extra selectivity of the non-base predicates (those that were left in the predicate list by getBasePredicates() that are not applied to the scan of the base conglomerate.
`void`	`putBasePredicates(org.apache.derby.iapi.sql.compile.OptimizablePredicateList predList, org.apache.derby.iapi.sql.compile.OptimizablePredicateList basePredicates)` Put back and base predicates that were removed from the list by getBasePredicates (see above).
`java.lang.String`	`resultSetMethodName(boolean bulkFetch)` Get the name of the result set method for base table scans
`int`	`scanCostType()` Get the costing type, for use with StoreCostController.getScanCost
`java.lang.String`	`toString()` Convert this Object to a human-readable String.

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

HashJoinStrategy

feasible

ignoreBulkFetch

multiplyBaseCostByOuterRows

getBasePredicates

nonBasePredicateSelectivity

putBasePredicates

estimateCost

maxCapacity

getName

scanCostType

resultSetMethodName

joinResultSetMethodName

halfOuterJoinResultSetMethodName

getScanArgs

divideUpPredicateLists

isHashJoin

doesMaterialization

findHashKeyColumns

toString

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