WindowFunctionNode (Apache Derby V10.14 Internals)

java.lang.Object
- org.apache.derby.impl.sql.compile.QueryTreeNode
- - org.apache.derby.impl.sql.compile.ValueNode
  - - org.apache.derby.impl.sql.compile.OperatorNode
    - - org.apache.derby.impl.sql.compile.UnaryOperatorNode
      - org.apache.derby.impl.sql.compile.WindowFunctionNode

All Implemented Interfaces:

Visitable

Direct Known Subclasses:

AggregateWindowFunctionNode, RowNumberFunctionNode
```
public abstract class WindowFunctionNode
extends UnaryOperatorNode
```
Superclass of any window function call.

Field Summary

Fields
Modifier and Type Field Description

private ResultColumn generatedRC

private ColumnReference generatedRef

private WindowNode window
- 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
- Fields inherited from class org.apache.derby.impl.sql.compile.UnaryOperatorNode
  K_BASE, K_XMLPARSE, K_XMLSERIALIZE, kind, methodName, operand, operator, receiverInterfaceType, resultInterfaceType, UnaryArgTypes, UnaryMethodNames, UnaryOperators, UnaryResultTypes
- Fields inherited from class org.apache.derby.impl.sql.compile.ValueNode
  transformed

Fields
Modifier and Type	Field	Description
`private ResultColumn`	`generatedRC`
`private ColumnReference`	`generatedRef`
`private WindowNode`	`window`

Constructor Summary

Constructors
Constructor	Description
`WindowFunctionNode(ValueNode op, java.lang.String functionName, WindowNode w, ContextManager cm)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) ValueNode`	`bindExpression(FromList fromList, SubqueryList subqueryList, java.util.List<AggregateNode> aggregates)`	ValueNode override.
`(package private) boolean`	`constantExpression(PredicateList whereClause)`	ValueNode override.
`private WindowDefinitionNode`	`definedWindow(WindowList windows, java.lang.String name)`
`(package private) ColumnReference`	`getGeneratedRef()`	Get the generated ColumnReference to this window function after the parent called replaceCallsWithColumnReferences().
`(package private) ValueNode`	`getNewNullResultExpression()`	Get the null result expression column.
`(package private) WindowNode`	`getWindow()`
`boolean`	`isConstantExpression()`	ValueNode override.
`void`	`printSubNodes(int depth)`	QueryTreeNode override.
`(package private) ValueNode`	`replaceCallsWithColumnReferences(ResultColumnList rcl, int tableNumber)`	Replace window function calls in the expression tree with a ColumnReference to that window function, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference.
`(package private) void`	`setWindow(WindowDefinitionNode wdn)`	Set window associated with this window function call.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from class org.apache.derby.impl.sql.compile.OperatorNode
pushSqlXmlUtil

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, referencesSessionSchema, resolveTableToSynonym, setBeginOffset, setEndOffset, setRefActionInfo, stackPrint, taggedWith, treePrint, treePrint, verifyClassExist

Methods inherited from class org.apache.derby.impl.sql.compile.UnaryOperatorNode
acceptChildren, addXmlOpMethodParams, bindOperand, bindParameter, categorize, generateExpression, getOperand, getOperatorString, getOrderableVariantType, getParameterOperand, getReceiverInterfaceName, isEquivalent, isSameNodeKind, preprocess, remapColumnReferencesToExpressions, setMethodName, setOperator, toString

Methods inherited from class org.apache.derby.impl.sql.compile.ValueNode
bindExpression, changeToCNF, checkIsBoolean, checkTopPredicatesForEqualsConditions, copyFields, eliminateNots, evaluateConstantExpressions, genEqualsFalseTree, generate, genIsNullTree, genSQLJavaSQLTree, getClone, getColumnName, getConstantValueAsObject, getDataValueFactory, getSchemaName, getSourceResultColumn, getTableName, getTablesReferenced, getTransformed, getTypeCompiler, getTypeId, getTypeServices, isBinaryEqualsOperatorNode, isBooleanFalse, isBooleanTrue, isCloneable, isInListProbeNode, isParameterNode, isRelationalOperator, optimizableEqualityNode, putAndsOnTop, requiresTypeFromContext, selectivity, setCollationInfo, setCollationInfo, setCollationUsingCompilationSchema, setCollationUsingCompilationSchema, setNullability, setTransformed, setType, setType, setType, updatableByCursor, verifyChangeToCNF, verifyEliminateNots, verifyPutAndsOnTop

- Field Detail
  - window
```
private WindowNode window
```
  - generatedRC
```
private ResultColumn generatedRC
```
  - generatedRef
```
private ColumnReference generatedRef
```
- Constructor Detail
  - WindowFunctionNode
```
WindowFunctionNode(ValueNode op,
                   java.lang.String functionName,
                   WindowNode w,
                   ContextManager cm)
            throws StandardException
```
    Parameters:
    
    op - operand (null for now)
    
    functionName - operator
    
    w - window node (definition or reference)
    
    cm - context manager
    
    Throws:
    
    StandardException
- Method Detail
  - isConstantExpression
```
public boolean isConstantExpression()
```
    ValueNode override.
    
    Overrides:
    
    isConstantExpression in class UnaryOperatorNode
    
    Returns:
    
    Whether or not this expression tree represents a constant expression.
    
    See Also:
    
    ValueNode.isConstantExpression()
  - constantExpression
```
boolean constantExpression(PredicateList whereClause)
```
    ValueNode override.
    
    Overrides:
    
    constantExpression in class UnaryOperatorNode
    
    Returns:
    
    True means this expression tree represents a constant value.
    
    See Also:
    
    ValueNode.isConstantExpression()
  - getWindow
```
WindowNode getWindow()
```
    Returns:
    
    window associated with this window function
  - setWindow
```
void setWindow(WindowDefinitionNode wdn)
```
    Set window associated with this window function call.
    
    Parameters:
    
    wdn - window definition
  - bindExpression
```
ValueNode bindExpression(FromList fromList,
                         SubqueryList subqueryList,
                         java.util.List<AggregateNode> aggregates)
                  throws StandardException
```
    ValueNode override.
    
    Overrides:
    
    bindExpression in class UnaryOperatorNode
    
    Parameters:
    
    fromList - The FROM list for the query this expression is in, for binding columns.
    
    subqueryList - The subquery list being built as we find SubqueryNodes
    
    aggregates - The aggregate list being built as we find AggregateNodes
    
    Returns:
    
    The new top of the expression tree.
    
    Throws:
    
    StandardException - Thrown on error
    
    See Also:
    
    ValueNode.bindExpression(org.apache.derby.impl.sql.compile.FromList, org.apache.derby.impl.sql.compile.SubqueryList, java.util.List<org.apache.derby.impl.sql.compile.AggregateNode>)
  - definedWindow
```
private WindowDefinitionNode definedWindow(WindowList windows,
                                           java.lang.String name)
```
    Returns:
    
    if name matches a defined window (in windows), return the definition of that window, else null.
  - printSubNodes
```
public void printSubNodes(int depth)
```
    QueryTreeNode override.
    
    Overrides:
    
    printSubNodes in class UnaryOperatorNode
    
    Parameters:
    
    depth - The depth of this node in the tree
    
    See Also:
    
    QueryTreeNode.printSubNodes(int)
  - replaceCallsWithColumnReferences
```
ValueNode replaceCallsWithColumnReferences(ResultColumnList rcl,
                                           int tableNumber)
                                    throws StandardException
```
    Replace window function calls in the expression tree with a ColumnReference to that window function, append the aggregate to the supplied RCL (assumed to be from the child ResultSetNode) and return the ColumnReference.
    
    Parameters:
    
    rcl - The RCL to append to.
    
    tableNumber - The tableNumber for the new ColumnReference
    
    Returns:
    
    ValueNode The (potentially) modified tree.
    
    Throws:
    
    StandardException - Thrown on error
  - getGeneratedRef
```
ColumnReference getGeneratedRef()
```
    Get the generated ColumnReference to this window function after the parent called replaceCallsWithColumnReferences().
    There are cases where this will not have been done because the tree has been re-written to eliminate the window function, e.g. for this query:
```
     SELECT * FROM t WHERE EXISTS
           (SELECT ROW_NUMBER() OVER () FROM t)
 
```
    in which case the top PRN of the subquery sitting over a WindowResultSetNode just contains a RC which is boolean constant true. This means that the replaceCallsWithColumnReferences will not have been called for this, so the returned generatedRef is null.
    Returns:
    
    the column reference
  - getNewNullResultExpression
```
ValueNode getNewNullResultExpression()
                              throws StandardException
```
    Get the null result expression column.
    
    Returns:
    
    the value node
    
    Throws:
    
    StandardException - on error

Class WindowFunctionNode

Field Summary

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

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

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

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

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

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

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

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

Field Detail

window

generatedRC

generatedRef

Constructor Detail

WindowFunctionNode

Method Detail

isConstantExpression

constantExpression

getWindow

setWindow

bindExpression

definedWindow

printSubNodes

replaceCallsWithColumnReferences

getGeneratedRef

getNewNullResultExpression