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

java.lang.Object
  org.apache.derby.impl.sql.compile.QueryTreeNode
      org.apache.derby.impl.sql.compile.QueryTreeNodeVector
          org.apache.derby.impl.sql.compile.SubqueryList

All Implemented Interfaces:

Node, Visitable

public class SubqueryList
extends QueryTreeNodeVector

A SubqueryList represents a list of subquerys within a specific clause (select, where or having) in a DML statement. It extends QueryTreeNodeVector.

Field Summary

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

AUTOINCREMENT_CREATE_MODIFY, AUTOINCREMENT_INC_INDEX, AUTOINCREMENT_IS_AUTOINCREMENT_INDEX, AUTOINCREMENT_START_INDEX, isPrivilegeCollectionRequired

Constructor Summary

SubqueryList()

Method Summary

void	addSubqueryNode(SubqueryNode subqueryNode) Add a subquery to the list.
(package private) void	decrementLevel(int decrement) Decrement (query block) level (0-based) for all of the tables in this subquery list.
void	markHavingSubqueries() Mark all of the subqueries in this list as being part of a having clause, so we can avoid flattenning later.
void	markWhereSubqueries() Mark all of the subqueries in this list as being part of a where clause so we can avoid flattening later if needed.
void	modifyAccessPaths() Modify the access paths for all subqueries in this list.
void	optimize(DataDictionary dataDictionary, double outerRows) Optimize the subqueries in this list.
void	preprocess(int numTables, FromList outerFromList, SubqueryList outerSubqueryList, PredicateList outerPredicateList) Preprocess a SubqueryList.
boolean	referencesSessionSchema() Return true if the node references SESSION schema tables (temporary or permanent)
boolean	referencesTarget(java.lang.String name, boolean baseTable) Search to see if a query references the specifed table name.
void	setPointOfAttachment(int pointOfAttachment) Set the point of attachment in all subqueries in this list.

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

acceptChildren, addElement, destructiveAppend, elementAt, indexOf, insertElementAt, nondestructiveAppend, printSubNodes, remove, removeAllElements, removeElement, removeElementAt, setElementAt, size

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

accept, bindOffsetFetch, bindRowMultiSet, bindUserCatalogType, bindUserType, checkReliability, checkReliability, convertDefaultNode, createTypeDependency, debugFlush, debugPrint, disablePrivilegeCollection, formatNodeString, foundString, generate, generateAuthorizeCheck, getBeginOffset, getClassFactory, getCompilerContext, getContextManager, getCursorInfo, getDataDictionary, getDependencyManager, getEndOffset, getExecutionFactory, getGenericConstantActionFactory, getIntProperty, getLanguageConnectionContext, getNodeFactory, getNodeType, getNullNode, getParameterTypes, getSchemaDescriptor, getSchemaDescriptor, getStatementType, getTableDescriptor, getTypeCompiler, init, init, init, init, init, init, init, init, init, init, init, init, init, init, isAtomic, isInstanceOf, isPrivilegeCollectionRequired, isSessionSchema, isSessionSchema, makeConstantAction, makeTableName, makeTableName, nodeHeader, orReliability, parseStatement, printLabel, resolveTableToSynonym, setBeginOffset, setContextManager, setEndOffset, setNodeType, setRefActionInfo, stackPrint, toString, treePrint, treePrint, verifyClassExist

Methods inherited from class java.lang.Object

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

Constructor Detail

SubqueryList

public SubqueryList()

Method Detail

addSubqueryNode

public void addSubqueryNode(SubqueryNode subqueryNode)
                     throws StandardException

Add a subquery to the list.

Parameters:

subqueryNode - A SubqueryNode to add to the list

Throws:

StandardException

preprocess

public void preprocess(int numTables,
                       FromList outerFromList,
                       SubqueryList outerSubqueryList,
                       PredicateList outerPredicateList)
                throws StandardException

Preprocess a SubqueryList. For now, we just preprocess each SubqueryNode in the list.

Parameters:

numTables - Number of tables in the DML Statement

outerFromList - FromList from outer query block

outerSubqueryList - SubqueryList from outer query block

outerPredicateList - PredicateList from outer query block

Throws:

StandardException - Thrown on error

optimize

public void optimize(DataDictionary dataDictionary,
                     double outerRows)
              throws StandardException

Optimize the subqueries in this list.

Parameters:

dataDictionary - The data dictionary to use for optimization

outerRows - The optimizer's estimate of the number of times this subquery will be executed.

Throws:

StandardException - Thrown on error

modifyAccessPaths

public void modifyAccessPaths()
                       throws StandardException

Modify the access paths for all subqueries in this list.

Throws:

StandardException - Thrown on error

See Also:

ResultSetNode.modifyAccessPaths()

referencesTarget

public boolean referencesTarget(java.lang.String name,
                                boolean baseTable)
                         throws StandardException

Search to see if a query references the specifed table name.

Parameters:

name - Table name (String) to search for.

baseTable - Whether or not name is for a base table

Returns:

true if found, else false

Throws:

StandardException - Thrown on error

referencesSessionSchema

public boolean referencesSessionSchema()
                                throws StandardException

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

setPointOfAttachment

public void setPointOfAttachment(int pointOfAttachment)
                          throws StandardException

Set the point of attachment in all subqueries in this list.

Parameters:

pointOfAttachment - The point of attachment

Throws:

StandardException - Thrown on error

decrementLevel

void decrementLevel(int decrement)

Decrement (query block) level (0-based) for all of the tables in this subquery list. This is useful when flattening a subquery.

Parameters:

decrement - The amount to decrement by.

markHavingSubqueries

public void markHavingSubqueries()

Mark all of the subqueries in this list as being part of a having clause, so we can avoid flattenning later.

markWhereSubqueries

public void markWhereSubqueries()

Mark all of the subqueries in this list as being part of a where clause so we can avoid flattening later if needed.