Apache Derby Database Engine and Embedded JDBC Driver 10.17.1.0 · org.apache.derby.impl.sql.compile.DeleteNode

Modifier and Type	Field and Description
private boolean	cascadeDelete
private static final String	COLUMNNAME
private boolean	deferred
private ConstantAction[]	dependentConstantActions
private StatementNode[]	dependentNodes
private FormatableBitSet	readColsBitSet
private FromTable	targetTable

Access	Constructor and Description
pack-priv	DeleteNode(TableName The name of the table to delete from targetTableName, ResultSetNode The query expression that will generate the rows to delete from the given table queryExpression, MatchingClauseNode Non-null if this DML is part of a MATCHED clause of a MERGE statement. matchingClause, ContextManager The context manager cm) Constructor for a DeleteNode.

Method Summary

Modifier and Type	Method and Description
public void	bindStatement() Overrides org.apache.derby.impl.sql.compile.StatementNode.bindStatement. Bind this DeleteNode.
private void	correlateAddedColumns(ResultColumnList rcl, FromTable fromTable)
pack-priv void	generate(ActivationClassBuilder The ActivationClassBuilder for the class being built acb, MethodBuilder The execute() method to be built mb) Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate. Code generation for delete.
private static FormatableBitSet	Returns: a FormatableBitSet of columns to be read out of the base table getDeleteReadMap(TableDescriptor baseTable, List<ConglomerateDescriptor> OUT: list of affected indices conglomerates, TriggerDescriptorList IN/OUT. Passed in as an empty list. Filled in as we go. relevantTriggers, boolean[] IN/OUT. true if the statement already needs deferred processing. set while evaluating this routine if a trigger requires deferred processing needsDeferredProcessing) Builds a bitmap of all columns which should be read from the Store in order to satisfy an DELETE statement.
private StatementNode	getDependentTableNode(String schemaName, String tableName, int refAction, ColumnDescriptorList cdl) In case of referential actions, we require to perform DML (UPDATE or DELETE) on the dependent tables.
private DeleteNode	getEmptyDeleteNode(String schemaName, String targetTableName)
private UpdateNode	getEmptyUpdateNode(String schemaName, String targetTableName, ColumnDescriptorList cdl)
pack-priv int	getPrivType() Overrides org.apache.derby.impl.sql.compile.DMLStatementNode.getPrivType. Return default privilege needed for this node.
public FormatableBitSet	Returns: a FormatableBitSet of columns to be read out of the base table getReadMap(DataDictionary the data dictionary to look in dd, TableDescriptor the base table descriptor baseTable) Gets the map of all columns which must be read out of the base table.
private ResultColumnList	getSetClause(ColumnDescriptorList cdl)
protected final int	Returns: the type of statement getStatementType() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.getStatementType. Return the type of statement, something from StatementType.
public ConstantAction	makeConstantAction() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.makeConstantAction. Compile constants that Execution will use
public void	optimizeStatement() Overrides org.apache.derby.impl.sql.compile.DMLModStatementNode.optimizeStatement. Generate an optimized QueryTree from a bound QueryTree.
public boolean	Returns: true if references SESSION schema tables, else false referencesSessionSchema() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.referencesSessionSchema. Return true if the node references SESSION schema tables (temporary or permanent)
pack-priv String	statementToString() Overrides org.apache.derby.impl.sql.compile.DMLModStatementNode.statementToString.

cascadeDelete	back to summary
private boolean cascadeDelete

COLUMNNAME	back to summary
private static final String COLUMNNAME

deferred	back to summary
private boolean deferred

dependentConstantActions	back to summary
private ConstantAction[] dependentConstantActions

dependentNodes	back to summary
private StatementNode[] dependentNodes

readColsBitSet	back to summary
private FormatableBitSet readColsBitSet

targetTable	back to summary
private FromTable targetTable

DeleteNode	back to summary
pack-priv DeleteNode(TableName targetTableName, ResultSetNode queryExpression, MatchingClauseNode matchingClause, ContextManager cm) Constructor for a DeleteNode. Parameters targetTableName:TableName The name of the table to delete from queryExpression:ResultSetNode The query expression that will generate the rows to delete from the given table matchingClause:MatchingClauseNode Non-null if this DML is part of a MATCHED clause of a MERGE statement. cm:ContextManager The context manager

Method Detail

bindStatement	back to summary
public void bindStatement() throws StandardException Overrides org.apache.derby.impl.sql.compile.StatementNode.bindStatement. Bind this DeleteNode. This means looking up tables and columns and getting their types, and figuring out the result types of all expressions, as well as doing view resolution, permissions checking, etc. If any indexes need to be updated, we add all the columns in the base table to the result column list, so that we can use the column values as look-up keys for the index rows to be deleted. Binding a delete will also massage the tree so that the ResultSetNode has column containing the RowLocation of the base row. Annotations @Override Exceptions StandardException: Thrown on error

bindStatement

back to summary

public void bindStatement() throws StandardException

Overrides org.apache.derby.impl.sql.compile.StatementNode.bindStatement.

Bind this DeleteNode. This means looking up tables and columns and getting their types, and figuring out the result types of all expressions, as well as doing view resolution, permissions checking, etc.

If any indexes need to be updated, we add all the columns in the base table to the result column list, so that we can use the column values as look-up keys for the index rows to be deleted. Binding a delete will also massage the tree so that the ResultSetNode has column containing the RowLocation of the base row.

Annotations

@Override

Exceptions

StandardException:: Thrown on error

correlateAddedColumns	back to summary
private void correlateAddedColumns(ResultColumnList rcl, FromTable fromTable) throws StandardException

generate	back to summary
pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb) throws StandardException Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate. Code generation for delete. The generated code will contain: o A static member for the (xxx)ResultSet with the RowLocations o The static member will be assigned the appropriate ResultSet within the nested calls to get the ResultSets. (The appropriate cast to the (xxx)ResultSet will be generated.) o The CurrentRowLocation() in SelectNode's select list will generate a new method for returning the RowLocation as well as a call to that method which will be stuffed in the call to the ProjectRestrictResultSet. o In case of referential actions, this function generate an array of resultsets on its dependent tables. Parameters acb:ActivationClassBuilder The ActivationClassBuilder for the class being built mb:MethodBuilder The execute() method to be built Annotations @Override Exceptions StandardException: Thrown on error

generate

back to summary

pack-priv void generate(ActivationClassBuilder acb, MethodBuilder mb) throws StandardException

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.generate.

Code generation for delete. The generated code will contain: o A static member for the (xxx)ResultSet with the RowLocations o The static member will be assigned the appropriate ResultSet within the nested calls to get the ResultSets. (The appropriate cast to the (xxx)ResultSet will be generated.) o The CurrentRowLocation() in SelectNode's select list will generate a new method for returning the RowLocation as well as a call to that method which will be stuffed in the call to the ProjectRestrictResultSet. o In case of referential actions, this function generate an array of resultsets on its dependent tables.

Parameters

acb:ActivationClassBuilder: The ActivationClassBuilder for the class being built
mb:MethodBuilder: The execute() method to be built

Annotations

@Override

Exceptions

StandardException:: Thrown on error

getDeleteReadMap	back to summary
private static FormatableBitSet getDeleteReadMap(TableDescriptor baseTable, List<ConglomerateDescriptor> conglomerates, TriggerDescriptorList relevantTriggers, boolean[] needsDeferredProcessing) throws StandardException Builds a bitmap of all columns which should be read from the Store in order to satisfy an DELETE statement. 1) finds all indices on this table 2) adds the index columns to a bitmap of affected columns 3) adds the index descriptors to a list of conglomerate descriptors. 4) finds all DELETE triggers on the table 5) if there are any DELETE triggers, then do one of the following a)If all of the triggers have MISSING referencing clause, then that means that the trigger actions do not have access to before and after values. In that case, there is no need to blanketly decide to include all the columns in the read map just because there are triggers defined on the table. b)Since one/more triggers have REFERENCING clause on them, get all the columns because we don't know what the user will ultimately reference. 6) adds the triggers to an evolving list of triggers Parameters conglomerates:List<ConglomerateDescriptor> OUT: list of affected indices relevantTriggers:TriggerDescriptorList IN/OUT. Passed in as an empty list. Filled in as we go. needsDeferredProcessing:boolean[] IN/OUT. true if the statement already needs deferred processing. set while evaluating this routine if a trigger requires deferred processing Returns:FormatableBitSet a FormatableBitSet of columns to be read out of the base table Exceptions StandardException: Thrown on error

getDeleteReadMap

back to summary

private static FormatableBitSet getDeleteReadMap(TableDescriptor baseTable, List<ConglomerateDescriptor> conglomerates, TriggerDescriptorList relevantTriggers, boolean[] needsDeferredProcessing) throws StandardException

Builds a bitmap of all columns which should be read from the Store in order to satisfy an DELETE statement. 1) finds all indices on this table 2) adds the index columns to a bitmap of affected columns 3) adds the index descriptors to a list of conglomerate descriptors. 4) finds all DELETE triggers on the table 5) if there are any DELETE triggers, then do one of the following a)If all of the triggers have MISSING referencing clause, then that means that the trigger actions do not have access to before and after values. In that case, there is no need to blanketly decide to include all the columns in the read map just because there are triggers defined on the table. b)Since one/more triggers have REFERENCING clause on them, get all the columns because we don't know what the user will ultimately reference. 6) adds the triggers to an evolving list of triggers

Parameters

conglomerates:List<ConglomerateDescriptor>: OUT: list of affected indices
relevantTriggers:TriggerDescriptorList: IN/OUT. Passed in as an empty list. Filled in as we go.
needsDeferredProcessing:boolean[]: IN/OUT. true if the statement already needs deferred processing. set while evaluating this routine if a trigger requires deferred processing

Returns:FormatableBitSet

a FormatableBitSet of columns to be read out of the base table

Exceptions

StandardException:: Thrown on error

getDependentTableNode	back to summary
private StatementNode getDependentTableNode(String schemaName, String tableName, int refAction, ColumnDescriptorList cdl) throws StandardException In case of referential actions, we require to perform DML (UPDATE or DELETE) on the dependent tables. Following function returns the DML Node for the dependent table.

getEmptyDeleteNode	back to summary
private DeleteNode getEmptyDeleteNode(String schemaName, String targetTableName) throws StandardException

getEmptyUpdateNode	back to summary
private UpdateNode getEmptyUpdateNode(String schemaName, String targetTableName, ColumnDescriptorList cdl) throws StandardException

getPrivType	back to summary
pack-priv int getPrivType() Overrides org.apache.derby.impl.sql.compile.DMLStatementNode.getPrivType. Doc from org.apache.derby.impl.sql.compile.DMLStatementNode.getPrivType. Return default privilege needed for this node. Other DML nodes can override this method to set their own default privilege. Returns:int true if the statement is atomic Annotations @Override

getPrivType

back to summary

pack-priv int getPrivType()

Overrides org.apache.derby.impl.sql.compile.DMLStatementNode.getPrivType.

Doc from org.apache.derby.impl.sql.compile.DMLStatementNode.getPrivType.

Return default privilege needed for this node. Other DML nodes can override this method to set their own default privilege.

Returns:int

true if the statement is atomic

Annotations

@Override

getReadMap	back to summary
public FormatableBitSet getReadMap(DataDictionary dd, TableDescriptor baseTable) throws StandardException Gets the map of all columns which must be read out of the base table. These are the columns needed to: o maintain indices o maintain foreign keys The returned map is a FormatableBitSet with 1 bit for each column in the table plus an extra, unsued 0-bit. If a 1-based column id must be read from the base table, then the corresponding 1-based bit is turned ON in the returned FormatableBitSet. Parameters dd:DataDictionary the data dictionary to look in baseTable:TableDescriptor the base table descriptor Returns:FormatableBitSet a FormatableBitSet of columns to be read out of the base table Exceptions StandardException: Thrown on error

getReadMap

back to summary

public FormatableBitSet getReadMap(DataDictionary dd, TableDescriptor baseTable) throws StandardException

Gets the map of all columns which must be read out of the base table. These are the columns needed to: o maintain indices o maintain foreign keys The returned map is a FormatableBitSet with 1 bit for each column in the table plus an extra, unsued 0-bit. If a 1-based column id must be read from the base table, then the corresponding 1-based bit is turned ON in the returned FormatableBitSet.

Parameters

dd:DataDictionary: the data dictionary to look in
baseTable:TableDescriptor: the base table descriptor

Returns:FormatableBitSet

a FormatableBitSet of columns to be read out of the base table

Exceptions

StandardException:: Thrown on error

getSetClause	back to summary
private ResultColumnList getSetClause(ColumnDescriptorList cdl) throws StandardException

getStatementType	back to summary
protected final int getStatementType() Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.getStatementType. Return the type of statement, something from StatementType. Returns:int the type of statement Annotations @Override

getStatementType

back to summary

protected final int getStatementType()

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.getStatementType.

Return the type of statement, something from StatementType.

Returns:int

the type of statement

Annotations

@Override

makeConstantAction	back to summary
public ConstantAction makeConstantAction() throws StandardException Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.makeConstantAction. Compile constants that Execution will use Annotations @Override Exceptions StandardException: Thrown on failure

makeConstantAction

back to summary

public ConstantAction makeConstantAction() throws StandardException

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.makeConstantAction.

Compile constants that Execution will use

Annotations

@Override

Exceptions

StandardException:: Thrown on failure

optimizeStatement	back to summary
public void optimizeStatement() throws StandardException Overrides org.apache.derby.impl.sql.compile.DMLModStatementNode.optimizeStatement. Doc from org.apache.derby.impl.sql.compile.DMLModStatementNode.optimizeStatement. Generate an optimized QueryTree from a bound QueryTree. Actually, it can annotate the tree in place rather than generate a new tree, but this interface allows the root node of the optimized QueryTree to be different from the root node of the bound QueryTree. For non-optimizable statements, this method is a no-op. Throws an exception if the tree is not bound, or if the binding is out of date. Annotations @Override Exceptions StandardException: Thrown on failure

optimizeStatement

back to summary

public void optimizeStatement() throws StandardException

Overrides org.apache.derby.impl.sql.compile.DMLModStatementNode.optimizeStatement.

Doc from org.apache.derby.impl.sql.compile.DMLModStatementNode.optimizeStatement.

Generate an optimized QueryTree from a bound QueryTree. Actually, it can annotate the tree in place rather than generate a new tree, but this interface allows the root node of the optimized QueryTree to be different from the root node of the bound QueryTree. For non-optimizable statements, this method is a no-op. Throws an exception if the tree is not bound, or if the binding is out of date.

Annotations

@Override

Exceptions

StandardException:: Thrown on failure

referencesSessionSchema	back to summary
public boolean referencesSessionSchema() throws StandardException Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.referencesSessionSchema. Return true if the node references SESSION schema tables (temporary or permanent) Returns:boolean true if references SESSION schema tables, else false Annotations @Override Exceptions StandardException: Thrown on error

referencesSessionSchema

back to summary

public boolean referencesSessionSchema() throws StandardException

Overrides org.apache.derby.impl.sql.compile.QueryTreeNode.referencesSessionSchema.

Return true if the node references SESSION schema tables (temporary or permanent)

Returns:boolean

true if references SESSION schema tables, else false

Annotations