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

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.RowResultSetNode

All Implemented Interfaces:

Optimizable, Visitable

public class RowResultSetNode

extends FromTable

A RowResultSetNode represents the result set for a VALUES clause.

Author:

Jerry Brenner

Field Summary

(package private) java.util.Vector	aggregateVector
(package private) OrderByList	orderByList
(package private) SubqueryList	subquerys

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

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

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

costEstimate, cursorTargetTable, insertSource, optimizer, referencedTableMap, resultColumns, resultSetNumber, scratchCostEstimate, statementResultSet

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

AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, beginOffset, endOffset

Constructor Summary

RowResultSetNode()

Method Summary

ResultSetNode	addNewPredicate(Predicate predicate) Add a new predicate to the list.
void	bindExpressions(FromList fromListParam) Bind the expressions in this RowResultSetNode.
void	bindExpressionsWithTables(FromList fromListParam) Bind the expressions in this ResultSetNode if it has tables.
ResultSetNode	bindNonVTITables(DataDictionary dataDictionary, FromList fromListParam) Bind the non VTI tables in this ResultSetNode.
void	bindTargetExpressions(FromList fromListParam) Bind the expressions in the target list.
void	bindUntypedNullsToResultColumns(ResultColumnList bindingRCL) Bind any untyped null nodes to the types in the given ResultColumnList.
private boolean	canWeCacheResults()
ResultSetNode	ensurePredicateList(int numTables) Ensure that the top of the RSN tree has a PredicateList.
CostEstimate	estimateCost(OptimizablePredicateList predList, ConglomerateDescriptor cd, CostEstimate outerCost, Optimizer optimizer, RowOrdering rowOrdering) Estimate the cost of scanning this Optimizable using the given predicate list with the given conglomerate.
boolean	flattenableInFromSubquery(FromList fromList) Evaluate whether or not the subquery in a FromSubquery is flattenable.
void	generate(ActivationClassBuilder acb, MethodBuilder mb) The generated ResultSet will be: RowResultSet -- for the VALUES clause
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.
ResultColumn	getMatchingColumn(ColumnReference columnReference) Try to find a ResultColumn in the table represented by this FromTable that matches the name in the given ColumnReference.
void	init(java.lang.Object valuesClause, java.lang.Object tableProperties) Initializer for a RowResultSetNode.
(package private) void	markOrderingDependent() Notify the underlying result set tree that the result is ordering dependent.
Optimizable	modifyAccessPath(JBitSet outerTables) Modify the access path for this Optimizable, as necessary.
ResultSetNode	modifyAccessPaths() Modify the access paths according to the decisions the optimizer made.
ResultSetNode	optimize(DataDictionary dataDictionary, PredicateList predicateList, double outerRows) Optimize this SelectNode.
(package private) void	optimizeSubqueries(DataDictionary dd, double rowCount) Optimize any subqueries that haven't been optimized any where else.
ResultSetNode	preprocess(int numTables, GroupByList gbl, FromList fromList) Put a ProjectRestrictNode on top of each FromTable in the FromList.
void	printSubNodes(int depth) Prints the sub-nodes of this object.
(package private) void	pushOrderByList(OrderByList orderByList) Push the order by list down from the cursor node into its child result set so that the optimizer has all of the information that it needs to consider sort avoidance.
(package private) void	replaceDefaults(TableDescriptor ttd, ResultColumnList tcl) Replace any DEFAULTs with the associated tree for the default.
(package private) boolean	returnsAtMostOneRow() Return whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics.
java.lang.String	statementToString()
java.lang.String	toString() Convert this object to a String.
void	verifySelectStarSubquery(FromList outerFromList, int subqueryType) Verify that a SELECT * is valid for this type of subquery.

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

areAllColumnsProjected, assignCostEstimate, canBeOrdered, considerSortAvoidancePath, convertAbsoluteToRelativeColumnPosition, cursorTargetTable, decrementLevel, feasibleJoinStrategy, fillInReferencedTableMap, flatten, forUpdate, getBaseTableName, getBestAccessPath, getBestSortAvoidancePath, getCostEstimate, getCurrentAccessPath, getFromTableByName, getLevel, getName, getNumColumnsReturned, getProperties, getResultColumnsForList, getSchemaDescriptor, getSchemaDescriptor, getScratchCostEstimate, getTableDescriptor, getTableName, getTableNumber, getTrulyTheBestAccessPath, getUserSpecifiedJoinStrategy, hashKeyColumns, hasTableNumber, initAccessPaths, initialCapacity, isBaseTable, isCoveringIndex, isFlattenableJoinNode, isMaterializable, isOneRowScan, isTargetTable, legalJoinOrder, loadFactor, LOJ_reorderable, markUpdatableByCursor, maxCapacity, memoryUsageOK, needsSpecialRCLBinding, nextAccessPath, optimizeIt, pullOptPredicates, pushExpressions, pushOptPredicate, rememberAsBest, rememberJoinStrategyAsBest, rememberSortAvoidancePath, resetJoinStrategies, setAllColumnsProjected, setCostEstimate, setHashKeyColumns, setLevel, setProperties, setTableNumber, startOptimizing, supportsMultipleInstantiations, tellRowOrderingAboutConstantColumns, transformOuterJoins, uniqueJoin, verifyProperties

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

accept, assignResultSetNumber, bindResultColumns, bindResultColumns, bindVTITables, changeAccessPath, closeMethodArgument, columnTypesAndLengthsMatch, considerMaterialization, enhanceRCLForInsert, generateNormalizationResultSet, generateResultSet, genNewRCForInsert, genNormalizeResultSetNode, genProjectRestrict, genProjectRestrict, genProjectRestrictForReordering, getAllResultColumns, getCostEstimate, getCursorTargetTable, getFinalCostEstimate, getFromList, getNewCostEstimate, getOptimizer, getReferencedTableMap, getResultColumns, getResultSetNumber, isNotExists, isOneRowResultSet, isOrderedOn, isPossibleDistinctScan, isUpdatableCursor, LOJgetReferencedTables, makeResultDescription, makeResultDescriptors, markAsCursorTargetTable, markForDistinctScan, markStatementResultSet, notCursorTargetTable, notFlattenableJoin, numDistinctAggregates, parseDefault, performMaterialization, projectResultColumns, referencesTarget, rejectParameters, rejectXMLValues, renameGeneratedResultNames, setInsertSource, setReferencedTableMap, setResultColumns, setResultToBooleanTrueNode, setTableConstructorTypes, subqueryReferencesTarget, updateTargetLockMode

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

bind, convertDefaultNode, debugFlush, debugPrint, executeSchemaName, executeStatementName, formatNodeString, foundString, generate, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getRowEstimate, getSchemaDescriptor, getSchemaDescriptor, getSPSName, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, needsSavepoint, nodeHeader, optimize, parseQueryText, printLabel, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, 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, getReferencedTableMap, getResultSetNumber

Field Detail

subquerys

SubqueryList subquerys

aggregateVector

java.util.Vector aggregateVector

orderByList

OrderByList orderByList

Constructor Detail

RowResultSetNode

public RowResultSetNode()

Method Detail

init

public void init(java.lang.Object valuesClause,
                 java.lang.Object tableProperties)

Initializer for a RowResultSetNode.

Overrides:

init in class FromTable

Parameters:

valuesClause - The result column list for the VALUES clause.

tableProperties - Properties list associated with the table

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

statementToString

public java.lang.String statementToString()

printSubNodes

public void printSubNodes(int depth)

Prints the sub-nodes of this object. See QueryTreeNode.java for how tree printing is supposed to work.

Overrides:

printSubNodes in class ResultSetNode

Parameters:

depth - The depth of this node in the tree

Returns:

Nothing

estimateCost

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

Description copied from interface: Optimizable

Estimate the cost of scanning this Optimizable using the given predicate list with the given conglomerate. It is assumed that the predicate list has already been classified. This cost estimate is just for one scan, not for the life of the query.

Specified by:

estimateCost in interface Optimizable

Overrides:

estimateCost in class FromTable

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)

bindNonVTITables

public ResultSetNode bindNonVTITables(DataDictionary dataDictionary,
                                      FromList fromListParam)
                               throws StandardException

Bind the non VTI tables in this ResultSetNode. This includes getting their descriptors from the data dictionary and numbering them.

Overrides:

bindNonVTITables in class ResultSetNode

Parameters:

dataDictionary - The DataDictionary to use for binding

fromListParam - FromList to use/append to.

Returns:

ResultSetNode

Throws:

StandardException - Thrown on error

bindExpressions

public void bindExpressions(FromList fromListParam)
                     throws StandardException

Bind the expressions in this RowResultSetNode. 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.

Returns:

Nothing

Throws:

StandardException - Thrown on error

bindExpressionsWithTables

public void bindExpressionsWithTables(FromList fromListParam)
                               throws StandardException

Bind the expressions in this ResultSetNode if it has tables. This means binding the sub-expressions, as well as figuring out what the return type is for each expression.

Overrides:

bindExpressionsWithTables in class ResultSetNode

Parameters:

fromListParam - FromList to use/append to.

Returns:

Nothing

Throws:

StandardException - Thrown on error

bindTargetExpressions

public void bindTargetExpressions(FromList fromListParam)
                           throws StandardException

Bind the expressions in the target list. This means binding the sub-expressions, as well as figuring out what the return type is for each expression. This is useful for EXISTS subqueries, where we need to validate the target list before blowing it away and replacing it with a SELECT true.

Overrides:

bindTargetExpressions in class ResultSetNode

Returns:

Nothing

Throws:

StandardException - Thrown on error

bindUntypedNullsToResultColumns

public void bindUntypedNullsToResultColumns(ResultColumnList bindingRCL)
                                     throws StandardException

Bind any untyped null nodes to the types in the given ResultColumnList.

Overrides:

bindUntypedNullsToResultColumns in class ResultSetNode

Parameters:

bindingRCL - The ResultColumnList with the types to bind to.

Throws:

StandardException - Thrown on error

getMatchingColumn

public ResultColumn getMatchingColumn(ColumnReference columnReference)
                               throws StandardException

Try to find a ResultColumn in the table represented by this FromTable 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

getExposedName

public java.lang.String getExposedName()
                                throws StandardException

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.

Throws:

StandardException - Thrown on error

verifySelectStarSubquery

public void verifySelectStarSubquery(FromList outerFromList,
                                     int subqueryType)
                              throws StandardException

Verify that a SELECT * is valid for this type of subquery.

Overrides:

verifySelectStarSubquery in class ResultSetNode

Parameters:

outerFromList - The FromList from the outer query block(s)

subqueryType - The subquery type

Returns:

None

Throws:

StandardException - Thrown on error

pushOrderByList

void pushOrderByList(OrderByList orderByList)

Push the order by list down from the cursor node into its child result set so that the optimizer has all of the information that it needs to consider sort avoidance.

Overrides:

pushOrderByList in class ResultSetNode

Parameters:

orderByList - The order by list

Returns:

Nothing.

preprocess

public ResultSetNode preprocess(int numTables,
                                GroupByList gbl,
                                FromList fromList)
                         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:

preprocess in class ResultSetNode

Parameters:

numTables - Number of tables in the DML Statement

gbl - The group by list, if any

fromList - The from list, if any

Returns:

The generated ProjectRestrictNode atop the original FromTable.

Throws:

StandardException - Thrown on error

ensurePredicateList

public ResultSetNode ensurePredicateList(int numTables)
                                  throws StandardException

Ensure that the top of the RSN tree has a PredicateList.

Overrides:

ensurePredicateList in class ResultSetNode

Parameters:

numTables - The number of tables in the query.

Returns:

ResultSetNode A RSN tree with a node which has a PredicateList on top.

Throws:

StandardException - Thrown on error

addNewPredicate

public ResultSetNode addNewPredicate(Predicate predicate)
                              throws StandardException

Add a new predicate to the list. This is useful when doing subquery transformations, when we build a new predicate with the left side of the subquery operator and the subquery's result column.

Overrides:

addNewPredicate in class ResultSetNode

Parameters:

predicate - The predicate to add

Returns:

ResultSetNode The new top of the tree.

Throws:

StandardException - Thrown on error

flattenableInFromSubquery

public boolean flattenableInFromSubquery(FromList fromList)

Evaluate whether or not the subquery in a FromSubquery is flattenable. Currently, a FSqry is flattenable if all of the following are true: o Subquery is a SelectNode or a RowResultSetNode (not a UnionNode) o It contains no top level subqueries. (RESOLVE - we can relax this) o It does not contain a group by or having clause o It does not contain aggregates. o There is at least one result set in the from list that is not a RowResultSetNode (the reason is to avoid having an outer SelectNode with an empty FromList.

Overrides:

flattenableInFromSubquery in class ResultSetNode

Parameters:

fromList - The outer from list

Returns:

boolean Whether or not the FromSubquery is flattenable.

optimize

public ResultSetNode optimize(DataDictionary dataDictionary,
                              PredicateList predicateList,
                              double outerRows)
                       throws StandardException

Optimize this SelectNode. This means choosing the best access path for each table, among other things.

Overrides:

optimize in class ResultSetNode

Parameters:

dataDictionary - The DataDictionary to use for optimization

predicateList - The predicate list to optimize against

outerRows - The number of outer joining rows

Returns:

ResultSetNode The top of the optimized tree

Throws:

StandardException - Thrown on error

modifyAccessPath

public Optimizable modifyAccessPath(JBitSet outerTables)
                             throws StandardException

Description copied from interface: Optimizable

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

Specified by:

modifyAccessPath in interface Optimizable

Overrides:

modifyAccessPath in class FromTable

Throws:

StandardException - Thrown on error

See Also:

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

modifyAccessPaths

public ResultSetNode modifyAccessPaths()
                                throws StandardException

Description copied from class: ResultSetNode

Modify the access paths according to the decisions the optimizer made. This can include adding project/restrict nodes, index-to-base-row nodes, etc.

Overrides:

modifyAccessPaths in class ResultSetNode

Returns:

The modified query tree

Throws:

StandardException - Thrown on error

See Also:

ResultSetNode.modifyAccessPaths()

returnsAtMostOneRow

boolean returnsAtMostOneRow()

Return whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics. (A RowResultSetNode and a SELECT with a non-grouped aggregate will return at most 1 row.)

Overrides:

returnsAtMostOneRow in class ResultSetNode

Returns:

Whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics.

generate

public void generate(ActivationClassBuilder acb,
                     MethodBuilder mb)
              throws StandardException

The generated ResultSet will be: RowResultSet -- for the VALUES clause

Overrides:

generate in class QueryTreeNode

Parameters:

acb - The ActivationClassBuilder for the class being built

mb - The method for the generated code to go into

Returns:

A compiled Expression returning a ResultSet

Throws:

StandardException - Thrown on error

replaceDefaults

void replaceDefaults(TableDescriptor ttd,
                     ResultColumnList tcl)
               throws StandardException

Replace any DEFAULTs with the associated tree for the default.

Overrides:

replaceDefaults in class ResultSetNode

Parameters:

ttd - The TableDescriptor for the target table.

tcl - The RCL for the target table.

Throws:

StandardException - Thrown on error

optimizeSubqueries

void optimizeSubqueries(DataDictionary dd,
                        double rowCount)
                  throws StandardException

Optimize any subqueries that haven't been optimized any where else. This is useful for a RowResultSetNode as a derived table because it doesn't get optimized otherwise.

Overrides:

optimizeSubqueries in class FromTable

Returns:

Nothing.

Throws:

StandardException - Thrown on error

markOrderingDependent

void markOrderingDependent()

Notify the underlying result set tree that the result is ordering dependent. (For example, no bulk fetch on an index if under an IndexRowToBaseRow.)

Overrides:

markOrderingDependent in class ResultSetNode

Returns:

Nothing.

canWeCacheResults

private boolean canWeCacheResults()
                           throws StandardException

Throws:

StandardException