RowResultSetNode (Apache Derby V10.14 Internals)

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
```
class RowResultSetNode
extends FromTable
```
A RowResultSetNode represents the result set for a VALUES clause.

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 java.util.List<AggregateNode>`	`aggregates`
`(package private) ResultSetNode.QueryExpressionClauses`	`qec`
`(package private) SubqueryList`	`subquerys`

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
`RowResultSetNode(ResultColumnList valuesClause, java.util.Properties tableProperties, ContextManager cm)`	Constructor for a RowResultSetNode.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) ResultSetNode`	`addNewPredicate(Predicate predicate)`	Add a new predicate to the list.
`(package private) void`	`adjustForSortElimination()`	Notify the underlying result set tree that the optimizer has chosen to "eliminate" a sort.
`(package private) void`	`bindExpressions(FromList fromListParam)`	Bind the expressions in this RowResultSetNode.
`(package private) void`	`bindExpressionsWithTables(FromList fromListParam)`	Bind the expressions in this ResultSetNode if it has tables.
`(package private) ResultSetNode`	`bindNonVTITables(DataDictionary dataDictionary, FromList fromListParam)`	Bind the non VTI tables in this ResultSetNode.
`(package private) void`	`bindTargetExpressions(FromList fromListParam)`	Bind the expressions in the target list.
`(package private) void`	`bindUntypedNullsToResultColumns(ResultColumnList bindingRCL)`	Bind any untyped null nodes to the types in the given ResultColumnList.
`private boolean`	`canWeCacheResults()`
`(package private) ResultSetNode`	`enhanceRCLForInsert(InsertNode target, boolean inOrder, int[] colMap)`	Modify the RCL of this node to match the target of the insert.
`(package private) 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.
`(package private) boolean`	`flattenableInFromSubquery(FromList fromList)`	Evaluate whether or not the subquery in a FromSubquery is flattenable.
`(package private) void`	`generate(ActivationClassBuilder acb, MethodBuilder mb)`	The generated ResultSet will be: RowResultSet -- for the VALUES clause
`(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) ResultColumn`	`getMatchingColumn(ColumnReference columnReference)`	Try to find a ResultColumn in the table represented by this FromTable that matches the name in the given ColumnReference.
`Optimizable`	`modifyAccessPath(JBitSet outerTables)`	Modify the access path for this Optimizable, as necessary.
`(package private) ResultSetNode`	`modifyAccessPaths()`	Modify the access paths according to the decisions the optimizer made.
`(package private) 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.
`(package private) ResultSetNode`	`preprocess(int numTables, GroupByList gbl, FromList fromList)`	Put a ProjectRestrictNode on top of each FromTable in the FromList.
`(package private) void`	`printSubNodes(int depth)`	Prints the sub-nodes of this object.
`(package private) void`	`pushOffsetFetchFirst(ValueNode offset, ValueNode fetchFirst, boolean hasJDBClimitClause)`	Push down the offset and fetch first parameters, if any, to this node.
`(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.
`void`	`pushQueryExpressionSuffix()`	Set up a new level for order by and fetch/offset clauses.
`boolean`	`referencesSessionSchema()`	Return true if the node references SESSION schema tables (temporary or permanent)
`(package private) void`	`replaceOrForbidDefaults(TableDescriptor ttd, ResultColumnList tcl, boolean allowDefaults)`	Replace any DEFAULTs with the associated tree for the default if allowed, or flag (when inside top level set operator nodes).
`(package private) boolean`	`returnsAtMostOneRow()`	Return whether or not this ResultSet tree is guaranteed to return at most 1 row based on heuristics.
`(package private) void`	`setTableConstructorTypes(ResultColumnList typeColumns)`	Set the type of each parameter in the result column list for this table constructor.
`(package private) java.lang.String`	`statementToString()`
`(package private) 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
acceptChildren, assignCostEstimate, canBeOrdered, columnsAreUpdatable, considerSortAvoidancePath, convertAbsoluteToRelativeColumnPosition, cursorTargetTable, decrementLevel, feasibleJoinStrategy, fillInReferencedTableMap, flatten, forUpdate, getBaseTableName, getBestAccessPath, getBestSortAvoidancePath, getCorrelationName, getCostEstimate, getCurrentAccessPath, getFinalCostEstimate, getFromTableByName, getLevel, getMergeTableID, getName, getNumColumnsReturned, getOrigTableName, getProperties, getResultColumnsForList, getSchemaDescriptor, getSchemaDescriptor, getScratchCostEstimate, getTableDescriptor, getTableName, getTableNumber, getTrulyTheBestAccessPath, getUserSpecifiedJoinStrategy, hashKeyColumns, hasLargeObjectColumns, hasTableNumber, initAccessPaths, initialCapacity, isBaseTable, isCoveringIndex, isFlattenableJoinNode, isJoinColumnForRightOuterJoin, isMaterializable, isOneRowScan, isTargetTable, legalJoinOrder, loadFactor, LOJ_reorderable, markUpdatableByCursor, maxCapacity, memoryUsageOK, needsSpecialRCLBinding, nextAccessPath, optimizeIt, pullOptPredicates, pushExpressions, pushOptPredicate, rememberAsBest, rememberJoinStrategyAsBest, rememberSortAvoidancePath, resetJoinStrategies, setCostEstimateCost, setHashKeyColumns, setLevel, setMergeTableID, setOrigTableName, setProperties, setTableNumber, startOptimizing, supportsMultipleInstantiations, tellRowOrderingAboutConstantColumns, toString, transformOuterJoins, uniqueJoin, updateBestPlanMap, verifyProperties

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 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, setRefActionInfo, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist

Methods inherited from class org.apache.derby.impl.sql.compile.ResultSetNode
adjustForSortElimination, assignResultSetNumber, bindResultColumns, bindResultColumns, bindVTITables, changeAccessPath, columnTypesAndLengthsMatch, considerMaterialization, generateNormalizationResultSet, generateResultSet, genProjectRestrict, genProjectRestrict, genProjectRestrictForReordering, getAllResultColumns, getCandidateFinalCostEstimate, getCostEstimate, getCursorTargetTable, getFromList, getNewCostEstimate, getOptimizer, getOptimizerImpl, getRCLForInsert, getReferencedTableMap, getResultColumns, getResultSetNumber, getScratchCostEstimate, isCursorTargetTable, isInsertSource, isNotExists, isOneRowResultSet, isOrderedOn, isPossibleDistinctScan, isStatementResultSet, isUpdatableCursor, LOJgetReferencedTables, makeResultDescription, makeResultDescriptors, markAsCursorTargetTable, markForDistinctScan, markStatementResultSet, modifyAccessPaths, notCursorTargetTable, notFlattenableJoin, numDistinctAggregates, parseDefault, performMaterialization, printQueryExpressionSuffixClauses, projectResultColumns, referencesTarget, rejectParameters, rejectXMLValues, renameGeneratedResultNames, setCandidateFinalCostEstimate, setCostEstimate, setCursorTargetTable, setInsertSource, setOptimizer, setReferencedTableMap, setResultColumns, setResultSetNumber, setResultToBooleanTrueNode, setScratchCostEstimate, subqueryReferencesTarget, updateTargetLockMode

Methods inherited from interface org.apache.derby.iapi.sql.compile.Visitable
accept, addTag, taggedWith

- Field Detail
  - subquerys
```
SubqueryList subquerys
```
  - aggregates
```
private java.util.List<AggregateNode> aggregates
```
  - qec
```
ResultSetNode.QueryExpressionClauses qec
```
- Constructor Detail
  - RowResultSetNode
```
RowResultSetNode(ResultColumnList valuesClause,
                 java.util.Properties tableProperties,
                 ContextManager cm)
```
    Constructor for a RowResultSetNode.
    
    Parameters:
    
    valuesClause - The result column list for the VALUES clause.
    
    tableProperties - Properties list associated with the table
    
    cm - The context manager
- Method Detail
  - statementToString
```
java.lang.String statementToString()
```
  - printSubNodes
```
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
  - referencesSessionSchema
```
public boolean referencesSessionSchema()
                                throws StandardException
```
    Description copied from class: QueryTreeNode
    
    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
  - enhanceRCLForInsert
```
ResultSetNode enhanceRCLForInsert(InsertNode target,
                                  boolean inOrder,
                                  int[] colMap)
                           throws StandardException
```
    Modify the RCL of this node to match the target of the insert.
    
    Overrides:
    
    enhanceRCLForInsert in class ResultSetNode
    
    Parameters:
    
    target - the target node for the insert
    
    inOrder - are source cols in same order as target cols?
    
    colMap - int array representation of correspondence between RCLs - colmap[i] = -1 -> missing in current RCL colmap[i] = j -> targetRCL(i) <-> thisRCL(j+1)
    
    Returns:
    
    a node that replaces this node and whose RCL matches the target RCL. May return this node if no changes to the RCL are needed, or if the RCL is modified in-place.
    
    Throws:
    
    StandardException - Thrown on error
  - 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
    
    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)
  - bindNonVTITables
```
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
```
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.
    
    Throws:
    
    StandardException - Thrown on error
  - bindExpressionsWithTables
```
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.
    
    Throws:
    
    StandardException - Thrown on error
  - bindTargetExpressions
```
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
    
    Throws:
    
    StandardException - Thrown on error
  - bindUntypedNullsToResultColumns
```
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
```
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
```
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
```
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
    
    Throws:
    
    StandardException - Thrown on error
  - pushQueryExpressionSuffix
```
public void pushQueryExpressionSuffix()
```
    Description copied from class: ResultSetNode
    
    Set up a new level for order by and fetch/offset clauses. See Javadoc for ResultSetNode.QueryExpressionClauses. Overridden by implementors of pushOrderByNode, pushOffsetFetchFirst.
    
    Overrides:
    
    pushQueryExpressionSuffix in class ResultSetNode
  - 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
  - pushOffsetFetchFirst
```
void pushOffsetFetchFirst(ValueNode offset,
                          ValueNode fetchFirst,
                          boolean hasJDBClimitClause)
```
    Push down the offset and fetch first parameters, if any, to this node.
    
    Overrides:
    
    pushOffsetFetchFirst in class ResultSetNode
    
    Parameters:
    
    offset - the OFFSET, if any
    
    fetchFirst - the OFFSET FIRST, if any
    
    hasJDBClimitClause - true if the clauses were added by (and have the semantics of) a JDBC limit clause
  - preprocess
```
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
```
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
```
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
```
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
```
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
    
    Parameters:
    
    outerTables - Bit map of the tables that are outer to this one in the join order.
    
    Returns:
    
    The (potentially new) Optimizable at the top of the tree.
    
    Throws:
    
    StandardException - Thrown on error
    
    See Also:
    
    Optimizable.modifyAccessPath(org.apache.derby.iapi.util.JBitSet)
  - modifyAccessPaths
```
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.
  - setTableConstructorTypes
```
void setTableConstructorTypes(ResultColumnList typeColumns)
                       throws StandardException
```
    Set the type of each parameter in the result column list for this table constructor.
    
    Overrides:
    
    setTableConstructorTypes in class ResultSetNode
    
    Parameters:
    
    typeColumns - The ResultColumnList containing the desired result types.
    
    Throws:
    
    StandardException - Thrown on error
  - generate
```
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
    
    Throws:
    
    StandardException - Thrown on error
  - replaceOrForbidDefaults
```
void replaceOrForbidDefaults(TableDescriptor ttd,
                             ResultColumnList tcl,
                             boolean allowDefaults)
                      throws StandardException
```
    Replace any DEFAULTs with the associated tree for the default if allowed, or flag (when inside top level set operator nodes). Subqueries are checked for illegal DEFAULTs elsewhere.
    
    Overrides:
    
    replaceOrForbidDefaults in class ResultSetNode
    
    Parameters:
    
    ttd - The TableDescriptor for the target table.
    
    tcl - The RCL for the target table.
    
    allowDefaults - true if allowed
    
    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
    
    Throws:
    
    StandardException - Thrown on error
  - 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()
  - canWeCacheResults
```
private boolean canWeCacheResults()
                           throws StandardException
```
    Throws:
    
    StandardException

Class RowResultSetNode

Nested Class Summary

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

Field Summary

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

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

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

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

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

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

Field Detail

subquerys

aggregates

qec

Constructor Detail

RowResultSetNode

Method Detail

statementToString

printSubNodes

referencesSessionSchema

enhanceRCLForInsert

estimateCost

bindNonVTITables

bindExpressions

bindExpressionsWithTables

bindTargetExpressions

bindUntypedNullsToResultColumns

getMatchingColumn

getExposedName

verifySelectStarSubquery

pushQueryExpressionSuffix

pushOrderByList

pushOffsetFetchFirst

preprocess

ensurePredicateList

addNewPredicate

flattenableInFromSubquery

optimize

modifyAccessPath

modifyAccessPaths

returnsAtMostOneRow

setTableConstructorTypes

generate

replaceOrForbidDefaults

optimizeSubqueries

adjustForSortElimination

canWeCacheResults