public final Class UpdateNode

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

Code generation for update. The generated code will contain: o A static member for the (xxx)ResultSet with the RowLocations and new update values 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 when generating the (xxx)ResultSet.

Parameters

acb:ActivationClassBuilder

The ActivationClassBuilder for the class being built

mb:MethodBuilder

The method for the execute() method to be built

Annotations

@Override

Exceptions

StandardException:

Thrown on error

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

Gets the map of all columns which must be read out of the base table. These are the columns needed to

:
• maintain indices
• maintain foreign keys
• maintain generated columns
• support Replication's Delta Optimization

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

updateColumnList:ResultColumnList

the rcl for the update. CANNOT BE NULL

affectedGeneratedColumns:ColumnDescriptorList

columns whose generation clauses mention columns being updated

Returns:FormatableBitSet

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

Exceptions

StandardException:

Thrown on error

Builds a bitmap of all columns which should be read from the Store in order to satisfy an UPDATE statement. Is passed a list of updated columns. Does the following: 1) finds all indices which overlap the updated columns 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 constraints which overlap the updated columns and adds the constrained columns to the bitmap 5) finds all triggers which overlap the updated columns. 6) Go through all those triggers from step 5 and for each one of those triggers, follow the rules below to decide which columns should be read. Rule1)If trigger column information is null, then read all the columns from trigger table into memory irrespective of whether there is any trigger action column information. 2 egs of such triggers create trigger tr1 after update on t1 for each row values(1); create trigger tr1 after update on t1 referencing old as oldt for each row insert into t2 values(2,oldt.j,-2); Rule2)If trigger column information is available but no trigger action column information is found and no REFERENCES clause is used for the trigger, then read all the columns identified by the trigger column. eg create trigger tr1 after update of c1 on t1 for each row values(1); Rule3)If trigger column information and trigger action column information both are not null, then only those columns will be read into memory. This is possible only for triggers created in release 10.9 or higher(with the exception of 10.7.1.1 where we did collect that information but because of corruption caused by those changes, we do not use the information collected by 10.7). Starting 10.9, we are collecting trigger action column informatoin so we can be smart about what columns get read during trigger execution. eg create trigger tr1 after update of c1 on t1 referencing old as oldt for each row insert into t2 values(2,oldt.j,-2); Rule4)If trigger column information is available but no trigger action column information is found but REFERENCES clause is used for the trigger, then read all the columns from the trigger table. This will cover soft-upgrade scenario for triggers created pre-10.9. eg trigger created prior to 10.9 create trigger tr1 after update of c1 on t1 referencing old as oldt for each row insert into t2 values(2,oldt.j,-2); 7) adds the triggers to an evolving list of triggers 8) finds all generated columns whose generation clauses mention the updated columns and adds all of the mentioned columns

Parameters

dd:DataDictionary

Data Dictionary

baseTable:TableDescriptor

Table on which update is issued

updateColumnList:ResultColumnList

a list of updated columns

conglomerates:List<ConglomerateDescriptor>

OUT: list of affected indices

relevantConstraints:ConstraintDescriptorList

IN/OUT. Empty list is passed in. We hang constraints on it as we go.

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 or constraint requires deferred processing

affectedGeneratedColumns:ColumnDescriptorList

columns whose generation clauses mention updated columns

Returns:FormatableBitSet

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

Exceptions

StandardException:

Thrown on error

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

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

Parameters

depth:int

The depth of this node in the tree

Annotations

@Override

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

Annotations

@Override