/*

   Derby - Class org.apache.derby.impl.sql.compile.DMLModStatementNode

   Licensed to the Apache Software Foundation (ASF) under one or more
   contributor license agreements.  See the NOTICE file distributed with
   this work for additional information regarding copyright ownership.
   The ASF licenses this file to you under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
   the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package	org.apache.derby.impl.sql.compile;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import org.apache.derby.catalog.DefaultInfo;
import org.apache.derby.catalog.UUID;
import org.apache.derby.iapi.error.StandardException;
import org.apache.derby.iapi.reference.ClassName;
import org.apache.derby.iapi.reference.SQLState;
import org.apache.derby.iapi.services.classfile.VMOpcode;
import org.apache.derby.iapi.services.compiler.MethodBuilder;
import org.apache.derby.iapi.services.context.ContextManager;
import org.apache.derby.iapi.services.io.FormatableBitSet;
import org.apache.derby.iapi.sql.StatementType;
import org.apache.derby.iapi.sql.compile.CompilerContext;
import org.apache.derby.iapi.sql.compile.OptimizerFactory;
import org.apache.derby.iapi.sql.compile.Parser;
import org.apache.derby.iapi.sql.compile.Visitable;
import org.apache.derby.iapi.sql.compile.Visitor;
import org.apache.derby.iapi.sql.conn.Authorizer;
import org.apache.derby.iapi.sql.conn.LanguageConnectionContext;
import org.apache.derby.iapi.sql.depend.Dependent;
import org.apache.derby.iapi.sql.dictionary.ColumnDescriptor;
import org.apache.derby.iapi.sql.dictionary.ColumnDescriptorList;
import org.apache.derby.iapi.sql.dictionary.ConglomerateDescriptor;
import org.apache.derby.iapi.sql.dictionary.ConstraintDescriptor;
import org.apache.derby.iapi.sql.dictionary.ConstraintDescriptorList;
import org.apache.derby.iapi.sql.dictionary.DataDictionary;
import org.apache.derby.iapi.sql.dictionary.ForeignKeyConstraintDescriptor;
import org.apache.derby.iapi.sql.dictionary.IndexRowGenerator;
import org.apache.derby.iapi.sql.dictionary.ReferencedKeyConstraintDescriptor;
import org.apache.derby.iapi.sql.dictionary.SchemaDescriptor;
import org.apache.derby.iapi.sql.dictionary.TableDescriptor;
import org.apache.derby.iapi.sql.dictionary.TriggerDescriptor;
import org.apache.derby.iapi.sql.dictionary.TriggerDescriptorList;
import org.apache.derby.iapi.store.access.TransactionController;
import org.apache.derby.iapi.types.DataTypeDescriptor;
import org.apache.derby.impl.sql.execute.FKInfo;
import org.apache.derby.impl.sql.execute.TriggerInfo;
import org.apache.derby.shared.common.sanity.SanityManager;

/**
 * A DMLStatement for a table modification: to wit, INSERT
 * UPDATE or DELETE.
 *
 */

abstract class DMLModStatementNode extends DMLStatementNode
{
//	protected DataDictionary	dataDictionary;
	protected FromVTI			targetVTI;
	protected TableName			targetTableName;
	protected ResultColumnList	resultColumnList;
	protected int 				lockMode;		// lock mode for the target table

	protected FKInfo[]			fkInfo;			// array of FKInfo structures
												// generated during bind
	protected TriggerInfo		triggerInfo;	// generated during bind
    TableDescriptor     targetTableDescriptor;


	/* The indexes that could be affected by this statement */
	public	IndexRowGenerator[] 		indicesToMaintain;
	public	long[]						indexConglomerateNumbers;
	public	String[]					indexNames;
	protected ConstraintDescriptorList relevantCdl;
    protected TriggerDescriptorList relevantTriggers;

	// PRIVATE
	private boolean			requiresDeferredProcessing;
	private	int				statementType;
	private boolean			bound;
	private ValueNode		checkConstraints;

	/* Info required to perform referential actions */
	protected String[] fkSchemaNames; // referencing schema names.
	protected String[] fkTableNames; // referencing table names.
	protected int[] fkRefActions;    //type of referential actions 
	protected ColumnDescriptorList[]  fkColDescriptors;
	protected long[] fkIndexConglomNumbers; //conglomerate number of the backing index
	protected  boolean isDependentTable;
	protected int[][] fkColArrays; 
	protected TableName synonymTableName;
    protected   MatchingClauseNode  matchingClause;


    /** Set of dependent tables for cascading deletes. */
    Set<String> dependentTables;

    DMLModStatementNode
        (
         ResultSetNode resultSet,
         MatchingClauseNode matchingClause,
         ContextManager cm
         )
    {
        super(resultSet, cm);
        this.matchingClause = matchingClause;
        statementType = getStatementType();
    }

	/**
     * Constructor for a DMLModStatementNode -- delegate to DMLStatementNode
	 *
	 * @param resultSet	A ResultSetNode for the result set of the
	 *			DML statement
     * @param matchingClause   Non-null if this DML is part of a MATCHED clause of a MERGE statement.
	 * @param statementType used by nodes that allocate a DMLMod directly
	 *			(rather than inheriting it).
     * @param cm        The context manager
	 */
    DMLModStatementNode
        (
         ResultSetNode resultSet,
         MatchingClauseNode matchingClause,
         int statementType,
         ContextManager cm
         )
	{
        super(resultSet, cm);
        this.matchingClause = matchingClause;
        this.statementType = statementType;
	}

    /** Returns true if this DMLModStatement a [ NOT ] MATCHED action of a MERGE statement */
    public  boolean inMatchingClause() { return matchingClause != null; }

	void setTarget(QueryTreeNode targetName)
	{
		if (targetName instanceof TableName)
		{
			this.targetTableName = (TableName) targetName;
		}
		else
		{
			if (SanityManager.DEBUG)
			{
				if (! (targetName instanceof FromVTI))
				{
					SanityManager.THROWASSERT(
						"targetName expected to be FromVTI, not " + 
						targetName.getClass().getName());
				}
			}
			this.targetVTI = (FromVTI) targetName;
			targetVTI.setTarget();
		}
	}

	/**
	 * If the DML is on a temporary table, generate the code to mark temporary table as modified in the current UOW.
	 * At rollback transaction (or savepoint), we will check if the temporary table was modified in that UOW.
	 * If yes, we will remove all the data from the temporary table
	 *
	 * @param acb	The ActivationClassBuilder for the class being built
	 *
	 * @exception StandardException		Thrown on error
	 */
	protected void generateCodeForTemporaryTable(ActivationClassBuilder acb)
		throws StandardException
	{
		if (targetTableDescriptor != null && targetTableDescriptor.getTableType() == TableDescriptor.GLOBAL_TEMPORARY_TABLE_TYPE &&
			targetTableDescriptor.isOnRollbackDeleteRows() == true)
		{
            MethodBuilder mb = acb.getExecuteMethod();
			mb.pushThis();
			mb.callMethod(VMOpcode.INVOKEINTERFACE, ClassName.Activation,
									"getLanguageConnectionContext", ClassName.LanguageConnectionContext, 0);
			mb.push(targetTableDescriptor.getName());
			mb.callMethod(VMOpcode.INVOKEINTERFACE, null, "markTempTableAsModifiedInUnitOfWork",
						"void", 1);
			mb.endStatement();
		}
	}

	/**
	 * Verify the target table.  Get the TableDescriptor
	 * if the target table is not a VTI.
	 *
	 * @exception StandardException		Thrown on error
	 */
	void verifyTargetTable()
		throws StandardException
	{
                DataDictionary dataDictionary = getDataDictionary();
		if (targetTableName != null)
		{
			/*
			** Get the TableDescriptor for the table we are inserting into
			*/
			SchemaDescriptor sdtc = getSchemaDescriptor(targetTableName.getSchemaName());

			targetTableDescriptor = getTableDescriptor(
							targetTableName.getTableName(), sdtc);

			if (targetTableDescriptor == null)
			{
				// Check if the reference is for a synonym.
				TableName synonymTab = resolveTableToSynonym(targetTableName);
				if (synonymTab == null)
					throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND, targetTableName);
				synonymTableName = targetTableName;
				targetTableName = synonymTab;
				sdtc = getSchemaDescriptor(targetTableName.getSchemaName());

				targetTableDescriptor = getTableDescriptor(synonymTab.getTableName(), sdtc);
				if (targetTableDescriptor == null)
					throw StandardException.newException(SQLState.LANG_TABLE_NOT_FOUND, targetTableName);
			}
			
            targetTableName.setSchemaName(sdtc.getSchemaName());

            switch (targetTableDescriptor.getTableType())
			{
			case TableDescriptor.VIEW_TYPE:
				// Views are currently not updatable
				throw StandardException.newException(SQLState.LANG_VIEW_NOT_UPDATEABLE, 
						targetTableName);
			
			case TableDescriptor.VTI_TYPE:
				// fall through - currently all vti tables are system tables.
			case TableDescriptor.SYSTEM_TABLE_TYPE:
				// System tables are not updatable
				throw StandardException.newException(SQLState.LANG_UPDATE_SYSTEM_TABLE_ATTEMPTED, 
						targetTableName);
				default:
					break;
				
			}

			/* We need to get some kind of table lock (IX here), to prevent
			 * another thread from adding a new index while we are binding,
			 * if we are a reader in DDL mode.  Just a row lock on system table
			 * SYSCONGLOMERATE is not enough: that wouldn't prevent another
			 * thread from adding a new entry.  Part of the fix for Beetle 3976.
			 * Same lock as in exec, compatible with row lock, for concurrency.
			 */
			targetTableDescriptor = lockTableForCompilation(targetTableDescriptor);

			getCompilerContext().createDependency(targetTableDescriptor);
		}
		else
		{
			/* VTI - VTIs in DML Mod are version 2 VTIs - They
			 * must implement java.sql.PreparedStatement and have
			 * the JDBC2.0 getMetaData() and getResultSetConcurrency()
			 * methods and return an updatable ResultSet.
			 */
            FromList dummyFromList = new FromList(getContextManager());
			targetVTI = (FromVTI) targetVTI.bindNonVTITables(dataDictionary, dummyFromList);
			targetVTI = (FromVTI) targetVTI.bindVTITables(dummyFromList);
		}
	}

	/**
	 *
	 * INSERT/UPDATE/DELETE are always atomic.
	 *
	 * @return true 
	 */	
    @Override
	public boolean isAtomic()
	{
		return true;
	}

	/**
	* Get a schema descriptor for the given table.
	* Uses this.targetTableName.
	*
	* @return Schema Descriptor
	*
	* @exception	StandardException	throws on schema name
	*						that doesn't exist	
	*/
    SchemaDescriptor getSchemaDescriptor() throws StandardException
	{
		SchemaDescriptor		sd;

		sd = getSchemaDescriptor(targetTableName.getSchemaName());

		return sd;
	}	

	/**
	  Get a map to efficiently find heap columns from a compressed set of
	  read columns. The returns a map such that

	  <PRE>
	  map[heapColId (0 based)] -&gt; readCol id (0 based)
	  </PRE>

	  @param column_map_length The number of columns(ints) in the map.
	  @param readColsBitSet A language style (1 based) bit set with bits for
	  read heap columns set.

	  RESOLVE: Replace this with a call to RowUtil when the store and
	  the language both use 0 base or 1 base offsets for columns. Today
	  we can't use the store function because we have a 1 based FormatableBitSet.
	  */
    static int[] getReadColMap(int column_map_length,
                               FormatableBitSet readColsBitSet)
	{
		if (readColsBitSet == null) return null;

        int partial_col_cnt = 0;
        int column_map[] = new int[column_map_length];
		int readColsBitSetSize = readColsBitSet.size();

        for (int base_index = 0; base_index < column_map.length; base_index++)
        {
			if (readColsBitSetSize > base_index && readColsBitSet.get(base_index+1))
				column_map[base_index] = partial_col_cnt++;
			else
				// this column map offset entry should never be referenced.
				column_map[base_index] = -1;
		}

        return(column_map);
	}

	/**
	 * Get and bind the ResultColumnList representing the columns in the
	 * target table, given the table's name.
	 *
	 * @exception StandardException		Thrown on error
	 */
	protected void getResultColumnList()
		throws StandardException
	{
		if (targetVTI == null)
		{
			getResultColumnList((ResultColumnList) null);
		}
		else
		{
			/* binding VTI - just point to VTI's RCL,
			 * which was already bound.
			 */
			resultColumnList = targetVTI.getResultColumns();
		}
	}

	/**
	 * Get and bind the ResultColumnList representing the columns in the
	 * target table, given the table's name.
	 *
	 * @exception StandardException		Thrown on error
	 */
	protected FromBaseTable getResultColumnList(ResultColumnList	inputRcl)
		throws StandardException
	{
		/* Get a ResultColumnList representing all the columns in the target */
        FromBaseTable fbt = new FromBaseTable(
                synonymTableName != null ? synonymTableName : targetTableName,
                null,
                null,
                null,
                getContextManager());
        if ( inMatchingClause() )
        {
            fbt.setMergeTableID( ColumnReference.MERGE_TARGET );
        }

		fbt.bindNonVTITables(
			getDataDictionary(),
            new FromList(getOptimizerFactory().doJoinOrderOptimization(),
                         getContextManager()));

		getResultColumnList(
							fbt,
							inputRcl
							);
		return fbt;
	}

	/**
	 * Get and bind the ResultColumnList representing the columns in the
	 * target table, given a FromTable for the target table.
	 *
	 * @exception StandardException		Thrown on error
	 */
	private void getResultColumnList(FromBaseTable	fromBaseTable,
										ResultColumnList	inputRcl)
		throws StandardException
	{
		if (inputRcl == null) 
		{
			resultColumnList = fromBaseTable.getAllResultColumns(null);
			resultColumnList.bindResultColumnsByPosition(targetTableDescriptor);
		}
		else
		{
			resultColumnList = fromBaseTable.getResultColumnsForList(null, inputRcl,
													fromBaseTable.getTableNameField());

			resultColumnList.bindResultColumnsByName(targetTableDescriptor,
													(DMLStatementNode) this);
		}
	}

    /**
     * Parse and bind the generating expressions of computed columns.
     *
     * @param dataDictionary    metadata
     * @param targetTableDescriptor metadata for the table that has the generated columns
     * @param sourceRCL  the tuple stream which drives the INSERT or UPDATE
     * @param targetRCL  the row in the table that's being INSERTed or UPDATEd
     * @param forUpdate true if this is an UPDATE. false otherwise.
     * @param updateResultSet more information on the tuple stream driving the UPDATE
     */
	void parseAndBindGenerationClauses
	(
		DataDictionary		dataDictionary,
		TableDescriptor		targetTableDescriptor,
		ResultColumnList	sourceRCL,
		ResultColumnList	targetRCL,
        boolean             forUpdate,
        ResultSetNode       updateResultSet
    )
		throws StandardException
	{
		CompilerContext 			compilerContext = getCompilerContext();
        int  count = targetRCL.size();

        for ( int i = 0; i < count; i++ )
        {
            ResultColumn rc = targetRCL.elementAt( i );

            //
            // For updates, there are two copies of the column in the row: a
            // before image and the actual value which will be set when we
            // update the row. We only want to compile a generation clause for
            // the value which will be updated.
            //
            if ( forUpdate && !rc.updated() ) { continue; }
            
            if ( rc.hasGenerationClause() )
            {
                ColumnDescriptor    colDesc = rc.getTableColumnDescriptor();
                DataTypeDescriptor  dtd = colDesc.getType();
                DefaultInfo             di = colDesc.getDefaultInfo();
                ValueNode   generationClause = parseGenerationClause( di.getDefaultText(), targetTableDescriptor );

                // insert CAST in case column data type is not same as the
                // resolved type of the generation clause
                generationClause =
                    new CastNode(generationClause, dtd, getContextManager());
                
                // Assignment semantics of implicit cast here:
                // Section 9.2 (Store assignment). There, General Rule 
                // 2.b.v.2 says that the database should raise an exception
                // if truncation occurs when stuffing a string value into a
                // VARCHAR, so make sure CAST doesn't issue warning only.
                ((CastNode)generationClause).setAssignmentSemantics();
                
                //
                // Unqualified function references should resolve to the
                // current schema at the time that the table was
                // created/altered. See DERBY-3945.
                //
                compilerContext.pushCompilationSchema(
                    getSchemaDescriptor(di.getOriginalCurrentSchema(), false));

				try {
                    bindRowScopedExpression(
                        getOptimizerFactory(),
                        getContextManager(),
                        targetTableDescriptor,
                        sourceRCL,
                        generationClause );
                }
                finally
                {
                    compilerContext.popCompilationSchema();
                }

                ResultColumn newRC = new ResultColumn(
                    generationClause.getTypeServices(),
                    generationClause,
                    getContextManager());

                // replace the result column in place
                newRC.setVirtualColumnId( i + 1 ); // column ids are 1-based
                newRC.setColumnDescriptor( targetTableDescriptor, colDesc );
                targetRCL.setElementAt( newRC, i );

                // if this is an update, then the result column may appear in the
                // source list as well. replace it there too and perform a
                // little extra binding so that check constraints will bind and
                // generate correctly if they reference the generated column
                if ( forUpdate )
                {
                    for ( int j = 0; j < sourceRCL.size(); j++ )
                    {
                        if ( rc == sourceRCL.elementAt( j ) )
                        {
                            newRC.setName( rc.getName() );
                            newRC.setResultSetNumber( updateResultSet.getResultSetNumber() );
                            sourceRCL.setElementAt( newRC, j );
                            
                        }
                    }   // end of loop through sourceRCL
                }   // end if this is an update statement
            }  // end if this is a generated column
            
        }   // end of loop through targetRCL
    }
    
 	/**
	  *	Parse the generation clause for a column.
	  *
	  *	@param	clauseText  Text of the generation clause
	  *
	  * @return	The parsed expression as a query tree.
	  *
	  * @exception StandardException		Thrown on failure
	  */
	public	ValueNode	parseGenerationClause
	(
     String				clauseText,
     TableDescriptor    td
    )
		throws StandardException
	{
		Parser						p;
		ValueNode					clauseTree;
		LanguageConnectionContext	lcc = getLanguageConnectionContext();

		/* Get a Statement to pass to the parser */

		/* We're all set up to parse. We have to build a compilable SQL statement
		 * before we can parse -  So, we goober up a VALUES defaultText.
		 */
		String select = "SELECT " + clauseText + " FROM " + td.getQualifiedName();
		
		/*
		** Get a new compiler context, so the parsing of the select statement
		** doesn't mess up anything in the current context (it could clobber
		** the ParameterValueSet, for example).
		*/
		CompilerContext newCC = lcc.pushCompilerContext();

		p = newCC.getParser();
				
		/* Finally, we can call the parser */
		// Since this is always nested inside another SQL statement, so topLevel flag
		// should be false
		Visitable qt = p.parseStatement(select);
		if (SanityManager.DEBUG)
		{
			if (! (qt instanceof CursorNode))
			{
				SanityManager.THROWASSERT(
					"qt expected to be instanceof CursorNode, not " +
					qt.getClass().getName());
			}
			CursorNode cn = (CursorNode) qt;
			if (! (cn.getResultSetNode() instanceof SelectNode))
			{
				SanityManager.THROWASSERT(
					"cn.getResultSetNode() expected to be instanceof SelectNode, not " +
					cn.getResultSetNode().getClass().getName());
			}
		}

        clauseTree = ((CursorNode) qt).getResultSetNode().getResultColumns().
                elementAt(0).getExpression();

		lcc.popCompilerContext(newCC);

		return	clauseTree;
	}

	/**
	 * Gets and binds all the constraints for an INSERT/UPDATE/DELETE.
	 * First finds the constraints that are relevant to this node.
	 * This is done by calling getAllRelevantConstriants().  If
	 * getAllRelevantConstraints() has already been called, then
	 * this list is used.  Then it creates appropriate 
	 * dependencies. Then binds check constraints.  It also 
	 * generates the array of FKInfo items that are used in
	 * code generation.

	 * Note: we have a new flag here to see if defer processing is enabled or
	 *       not, the only scenario that is disabled is when we reapply the
	 *		 reply message we get from the source
	 *
	 *
	 * @param dataDictionary		The DataDictionary
	 * @param targetTableDescriptor	The TableDescriptor
	 * @param dependent			Parent object that will depend on all the constraints
	 *							that we look up. If this argument is null, then we
	 *							use the default dependent (the statement being compiled).
	 * @param sourceRCL				RCL of the table being changed
	 * @param changedColumnIds		If null, all columns being changed, otherwise array
	 *								of 1-based column ids for columns being changed
	 * @param readColsBitSet		bit set for the read scan
	 * @param includeTriggers		whether triggers are included in the processing
     * @param hasDeferrableCheckConstraints
     *                        OUT semantics: set element 0 to true if the
     *                        target table has any deferrable CHECK constraints
	 *
	 * @return	The bound, ANDed check constraints as a query tree.
	 *
	 * @exception StandardException		Thrown on failure
	 */
	ValueNode bindConstraints
	(
		DataDictionary		dataDictionary,
        OptimizerFactory    optimizerFactory,
		TableDescriptor		targetTableDescriptor,
		Dependent			dependent,
		ResultColumnList	sourceRCL,
		int[]				changedColumnIds,
		FormatableBitSet				readColsBitSet,
        boolean             includeTriggers,
        boolean[]           hasDeferrableCheckConstraints
    )
		throws StandardException
	{
		bound = true;

		/* Nothing to do if updatable VTI */
		if (targetVTI != null)
		{
			return null;
		}

        CompilerContext compilerContext = getCompilerContext();
        
        // Do not need privileges to execute constraints
		compilerContext.pushCurrentPrivType( Authorizer.NULL_PRIV);
		try {
			getAllRelevantConstraints(dataDictionary, 	
											targetTableDescriptor, 
											changedColumnIds);
			createConstraintDependencies(dataDictionary, relevantCdl, dependent);
			generateFKInfo(relevantCdl, dataDictionary, targetTableDescriptor, readColsBitSet);

			getAllRelevantTriggers(dataDictionary, targetTableDescriptor,
							   changedColumnIds, includeTriggers);
			createTriggerDependencies(relevantTriggers, dependent);
            generateTriggerInfo(relevantTriggers);

            checkConstraints = generateCheckTree(
                    relevantCdl,
                    targetTableDescriptor,
                    hasDeferrableCheckConstraints);

            if (checkConstraints != null)
			{
                SchemaDescriptor    originalCurrentSchema = targetTableDescriptor.getSchemaDescriptor();
                compilerContext.pushCompilationSchema( originalCurrentSchema );

                try {
                    bindRowScopedExpression(optimizerFactory,
                                            getContextManager(),
                                            targetTableDescriptor,
                                            sourceRCL,
                                            checkConstraints);
                }
                finally
                {
                    compilerContext.popCompilationSchema();
                }
			}
		}
		finally
		{
			compilerContext.popCurrentPrivType();
		}

		return	checkConstraints;
	}

	/**
	 * Binds an already parsed expression that only involves columns in a single
	 * row. E.g., a check constraint or a generation clause.
	 *
     * @param optimizerFactory      The optimizer factory
     * @param cm                    The context manager
     * @param targetTableDescriptor The TableDescriptor for the constrained
     *                              table
     * @param sourceRCL             Result columns
     * @param expression            Parsed query tree for row scoped expression
	 *
	 * @exception StandardException		Thrown on failure
	 */
	static void	bindRowScopedExpression
	(
        OptimizerFactory    optimizerFactory,
        ContextManager      cm,
		TableDescriptor		targetTableDescriptor,
		ResultColumnList	sourceRCL,
		ValueNode			expression
    )
		throws StandardException
	{

        TableName targetTableName = makeTableName(
                cm,
                targetTableDescriptor.getSchemaName(),
                targetTableDescriptor.getName());

		/* We now have the expression as a query tree.  Now, we prepare
		 * to bind that query tree to the source's RCL.  That way, the
		 * generated code for the expression will be evaluated against the
		 * source row to be inserted into the target table or
		 * against the after portion of the source row for the update
		 * into the target table.
		 *		o  Goober up a new FromList which has a single table,
		 *		   a goobered up FromBaseTable for the target table
		 *		   which has the source's RCL as it RCL.
		 *		   (This allows the ColumnReferences in the expression
		 *		   tree to be bound to the right RCs.)
		 *
	 	 * Note that in some circumstances we may not actually verify
		 * the expression against the source RCL but against a temp
		 * row source used for deferred processing because of a trigger.
		 * In this case, the caller of bindConstraints (UpdateNode)
		 * has chosen to pass in the correct RCL to bind against.
		 */
        FromList fakeFromList =
            new FromList(optimizerFactory.doJoinOrderOptimization(), cm);

        FromBaseTable table = new FromBaseTable(
                targetTableName,
                null,
                sourceRCL,
                null,
                cm);
		table.setTableNumber(0);
		fakeFromList.addFromTable(table);

		// Now we can do the bind.
        expression.bindExpression(
                fakeFromList,
                (SubqueryList) null,
                (List<AggregateNode>) null);
	}

	/**
	 * Determine whether or not there are check constraints on the
	 * specified table.
	 *
	 * @param dd	The DataDictionary to use
	 * @param td	The TableDescriptor for the table
	 *
	 * @return Whether or not there are check constraints on the specified table.
	 *
	 * @exception StandardException		Thrown on failure
	 */
	protected boolean hasCheckConstraints(DataDictionary dd,
										  TableDescriptor td)
		throws StandardException
	{
		ConstraintDescriptorList cdl = dd.getConstraintDescriptors(td);
        if (cdl == null)
            return false;
		ConstraintDescriptorList ccCDL = cdl.getSubList(DataDictionary.CHECK_CONSTRAINT);

		return (ccCDL.size() > 0);
	}

	/**
	 * Determine whether or not there are generated columns in the
	 * specified table.
	 *
	 * @param td	The TableDescriptor for the table
	 *
	 * @return Whether or not there are generated columns in the specified table.
	 *
	 * @exception StandardException		Thrown on failure
	 */
	protected boolean hasGenerationClauses(TableDescriptor td)
		throws StandardException
	{
		ColumnDescriptorList list= td.getGeneratedColumns();

		return (list.size() > 0);
	}


	/**
	 * Get the ANDing of all appropriate check constraints as 1 giant query tree.
	 *
	 * Makes the calling object (usually a Statement) dependent on all the constraints.
	 *
     * @param cdl               The constraint descriptor list
	 * @param td				The TableDescriptor
	 *
	 * @return	The ANDing of all appropriate check constraints as a query tree.
	 *
	 * @exception StandardException		Thrown on failure
	 */
	private	ValueNode generateCheckTree
	(
		ConstraintDescriptorList	cdl,
        TableDescriptor             td,
        boolean[]                   hasDeferrable
    )
		throws StandardException
	{
		ConstraintDescriptorList	ccCDL = cdl.getSubList(DataDictionary.CHECK_CONSTRAINT);
		int							ccCDLSize = ccCDL.size();
		ValueNode					checkTree = null;

        for (ConstraintDescriptor cd : ccCDL) {
            if (cd.deferrable()) {
                hasDeferrable[0] = true;
                break;
            }
        }


		// Get the text of all the check constraints
		for (int index = 0; index < ccCDLSize; index++)
		{
			ConstraintDescriptor cd = ccCDL.elementAt(index);

			String constraintText = cd.getConstraintText();

			// Get the query tree for this constraint
			ValueNode oneConstraint = 
				parseCheckConstraint(constraintText, td);

			// Put a TestConstraintNode above the constraint tree
           TestConstraintNode tcn = new TestConstraintNode(
					oneConstraint,
					SQLState.LANG_CHECK_CONSTRAINT_VIOLATED,
					td.getQualifiedName(),
                    cd,
					getContextManager());
					
			// Link consecutive TestConstraintNodes with AND nodes
			if (checkTree == null)
			{
				checkTree = tcn;
			}
			else
			{
               if (hasDeferrable[0]) {
                   checkTree = new AndNoShortCircuitNode(
                       tcn, checkTree, getContextManager());
               } else {
                   checkTree = new AndNode(tcn, checkTree, getContextManager());
               }
			}
		}

		return checkTree;
	}
	
	/**
	 * Generate the FKInfo structures used during code generation.
	 * For each constraint that isn't a check constraint, add another
	 * one of these FKInfo structures and then package them up into
	 * a single array.
	 *
	 * @param cdl				The constraint descriptor list
	 * @param dd				The DataDictionary
	 * @param td				The TableDescriptor
	 * @param readColsBitSet 	columns read
	 *
	 * @exception StandardException		Thrown on failure
	 */
	private void generateFKInfo 
	(
		ConstraintDescriptorList	cdl,
		DataDictionary				dd, 
		TableDescriptor				td,
		FormatableBitSet						readColsBitSet
    )
		throws StandardException
	{
        ArrayList<FKInfo>         fkList = new ArrayList<FKInfo>();
		int 								type;
        UUID[]                              uuids;
        long[]                              conglomNumbers;
        String[]                            fkNames;
		ConstraintDescriptorList			fkcdl;
		ReferencedKeyConstraintDescriptor	refcd;
		boolean[]							isSelfReferencingFK;
		ConstraintDescriptorList			activeList = dd.getActiveConstraintDescriptors(cdl);
		int[]								rowMap = getRowMap(readColsBitSet, td);
        int[]                               raRules;
        boolean[]                           deferrable;
        UUID[]                              fkIds;
		ArrayList<String>              refSchemaNames = new ArrayList<String>(1);
		ArrayList<String>              refTableNames = new ArrayList<String>(1);
		ArrayList<Long>               refIndexConglomNum = new ArrayList<Long>(1);
		ArrayList<Integer>            refActions = new ArrayList<Integer>(1);
		ArrayList<ColumnDescriptorList> refColDescriptors = new ArrayList<ColumnDescriptorList>(1);
		ArrayList<int[]>                fkColMap = new ArrayList<int[]>(1);
		int activeSize = activeList.size();
		for (int index = 0; index < activeSize; index++)
		{
			ConstraintDescriptor cd = activeList.elementAt(index);

			if (cd instanceof ForeignKeyConstraintDescriptor)
			{
				/*
				** We are saving information for checking the
				** primary/unique key that is referenced by this
				** foreign key, so type is FOREIGN KEY.
				*/	
				type = FKInfo.FOREIGN_KEY;
				refcd = ((ForeignKeyConstraintDescriptor)cd).getReferencedConstraint();
				uuids = new UUID[1];
                deferrable = new boolean[1];
                fkIds = new UUID[1];
				conglomNumbers = new long[1];
				fkNames = new String[1];
				isSelfReferencingFK = new boolean[1];
				raRules = new int[1];
                fkSetupArrays(
                    dd, (ForeignKeyConstraintDescriptor)cd,
                    0, uuids, conglomNumbers,
                    fkNames, isSelfReferencingFK, raRules, deferrable, fkIds);

				// oops, get the right constraint name -- for error
				// handling we want the FK name, not refcd name
				fkNames[0] = cd.getConstraintName();
			}
			else if (cd instanceof ReferencedKeyConstraintDescriptor)
			{	
				refcd = (ReferencedKeyConstraintDescriptor)cd;

				/*
				** We are saving information for checking the
				** foreign key(s) that is dependent on this referenced
				** key, so type is REFERENCED KEY.
				*/	
				type = FKInfo.REFERENCED_KEY;
				fkcdl = dd.getActiveConstraintDescriptors
					( ((ReferencedKeyConstraintDescriptor)cd).getForeignKeyConstraints(ConstraintDescriptor.ENABLED) );
	
				int size = fkcdl.size();
				if (size == 0) 
				{ 
					continue; 
				}

				uuids = new UUID[size];
                deferrable = new boolean[size];
                fkIds = new UUID[size];
				fkNames = new String[size];
				conglomNumbers = new long[size];
				isSelfReferencingFK = new boolean[size];
				raRules = new int[size];
				TableDescriptor fktd;
				ColumnDescriptorList coldl;
				int[] refColumns; 
				ColumnDescriptor cold; 
				int[] colArray = remapReferencedColumns(cd, rowMap);
				for (int inner = 0; inner < size; inner++)
				{
                    ForeignKeyConstraintDescriptor fkcd =
                        (ForeignKeyConstraintDescriptor) fkcdl.elementAt(inner);
                    fkSetupArrays(
                        dd, fkcd,
                        inner, uuids, conglomNumbers, fkNames,
                        isSelfReferencingFK, raRules, deferrable, fkIds);

					if((raRules[inner] == StatementType.RA_CASCADE) || 
					   (raRules[inner] ==StatementType.RA_SETNULL))
					{
						//find  the referencing  table Name
						fktd = fkcd.getTableDescriptor();
						refSchemaNames.add(fktd.getSchemaName());
						refTableNames.add(fktd.getName());
                        refActions.add(Integer.valueOf(raRules[inner]));
						//find the referencing column name required for update null.
						refColumns = fkcd.getReferencedColumns();
						coldl = fktd.getColumnDescriptorList();
						ColumnDescriptorList releventColDes = new ColumnDescriptorList();
						for(int i = 0 ; i < refColumns.length; i++)
						{
                            cold = coldl.elementAt(refColumns[i]-1);
							releventColDes.add(cold);
						}
						refColDescriptors.add(releventColDes);
                        refIndexConglomNum.add(
                            Long.valueOf(conglomNumbers[inner]));
						fkColMap.add(colArray);
					}
				}
			}
			else
			{
				continue;
			}

            final TableDescriptor   pktd = refcd.getTableDescriptor();
            final UUID pkIndexId = refcd.getIndexId();
            final ConglomerateDescriptor pkIndexConglom =
                    pktd.getConglomerateDescriptor(pkIndexId);

            final TableDescriptor refTd = cd.getTableDescriptor();

            fkList.add(
                new FKInfo(
                    fkNames,                // foreign key names
                    cd.getSchemaDescriptor().getSchemaName(),
                    refTd.getName(),        // table being modified
                    statementType,          // INSERT|UPDATE|DELETE
                    type,                   // FOREIGN_KEY|REFERENCED_KEY
                    pkIndexId,              // referenced backing index uuid
                    pkIndexConglom.getConglomerateNumber(),
                                            // referenced backing index conglom
                    refcd.getUUID(),
                    refcd.deferrable(),     // referenced constraint is
                                            // deferrable?
                    uuids,                  // fk backing index uuids
                    conglomNumbers,         // fk backing index congloms
                    isSelfReferencingFK,    // is self ref array of bool
                    remapReferencedColumns(cd, rowMap),
                                            // columns referenced by key
                    dd.getRowLocationTemplate(getLanguageConnectionContext(),
                                              refTd),
                                            // row location template for table
                                            // being modified
                    raRules,                // referential action rules
                    deferrable,             // deferrable flags
                    fkIds));                // UUID of fks

		}
		
        // Now convert the list into an array.
        if (!fkList.isEmpty()) {
            fkInfo = fkList.toArray(new FKInfo[fkList.size()]);
        }

        // Convert the ref action info lists to arrays.
		int size = refActions.size();
		if (size > 0)
		{
			fkTableNames = new String[size];
			fkSchemaNames = new String[size];
			fkRefActions  = new int[size];
			fkColDescriptors = new ColumnDescriptorList[size];
			fkIndexConglomNumbers = new long[size];
			fkColArrays = new int[size][];
			for (int i = 0; i < size; i++)
			{
				fkTableNames[i] = refTableNames.get(i);
				fkSchemaNames[i] = refSchemaNames.get(i);
				fkRefActions[i]  = (refActions.get(i)).intValue();
				fkColDescriptors[i] =
					refColDescriptors.get(i);
				fkIndexConglomNumbers[i] =
					(refIndexConglomNum.get(i)).longValue();
				fkColArrays[i] = (fkColMap.get(i));
			}
		}		

	}

	/*
	** Simple little helper method
	*/	
	private void fkSetupArrays
	(
		DataDictionary						dd,
		ForeignKeyConstraintDescriptor 		fkcd,
		int									index,
		UUID[]								uuids,
		long[]								conglomNumbers,
		String[]							fkNames,
		boolean[]							isSelfReferencingFK,
        int[]                               raRules,
        boolean[]                           isDeferrable,
        UUID[]                              fkIds
	)
		throws StandardException
	{
		fkNames[index] = fkcd.getConstraintName();
		uuids[index] = fkcd.getIndexId();
        isDeferrable[index] = fkcd.deferrable();
        fkIds[index] = fkcd.getUUID();
		conglomNumbers[index] = fkcd.getIndexConglomerateDescriptor(dd).getConglomerateNumber();
		isSelfReferencingFK[index] = fkcd.isSelfReferencingFK();
		if(statementType == StatementType.DELETE)
			raRules[index] = fkcd.getRaDeleteRule();
		else if(statementType == StatementType.UPDATE)
			raRules[index] = fkcd.getRaUpdateRule();
	}

	/**
	 * Generate the TriggerInfo structures used during code generation.
	 *
	 * @param triggerList				The trigger descriptor list
	 */
    private void generateTriggerInfo(TriggerDescriptorList triggerList)
	{	
        if ((triggerList != null) && (!triggerList.isEmpty()))
		{
            triggerInfo = new TriggerInfo(triggerList);
		}
	}

	/**
	 * Return the FKInfo structure.  Just  a little wrapper
	 * to make sure we don't try to access it until after
	 * binding.
	 *
	 * @return the array of fkinfos
	 */
    FKInfo[] getFKInfo()
	{
		if (SanityManager.DEBUG)
		{
			SanityManager.ASSERT(bound, "attempt to access FKInfo "+
					"before binding");
		}
		return fkInfo;
	}

	/**
	 * Return the TriggerInfo structure.  Just  a little wrapper
	 * to make sure we don't try to access it until after
	 * binding.
	 *
	 * @return the trigger info
	 */
    TriggerInfo getTriggerInfo()
	{
		if (SanityManager.DEBUG)
		{
			SanityManager.ASSERT(bound, "attempt to access TriggerInfo "+
					"before binding");
		}
		return triggerInfo;
	}

	/**
	 * Get the check constraints for this node
	 *
	 * @return the check constraints, may be null
	 */
    ValueNode getCheckConstraints()
	{
		if (SanityManager.DEBUG)
		{
			SanityManager.ASSERT(bound, "attempt to access FKInfo "+
					"before binding");
		}
		return checkConstraints;
	}	
			
	/**
	 * Makes the calling object (usually a Statement) dependent on all the constraints.
	 *
	 * @param tdl				The trigger descriptor list
	 * @param dependent			Parent object that will depend on all the constraints
	 *							that we look up. If this argument is null, then we
	 *							use the default dependent (the statement being compiled).
	 *
	 * @exception StandardException		Thrown on failure
	 */
	private void createTriggerDependencies
	(
        TriggerDescriptorList       tdl,
		Dependent					dependent
	)
		throws StandardException
	{
		CompilerContext 			compilerContext = getCompilerContext();

        for (TriggerDescriptor td : tdl) {
            /*
            ** The dependent now depends on this trigger.
            ** The default dependent is the statement being compiled.
            */
            if (dependent == null) {
                compilerContext.createDependency(td);
            } else {
                compilerContext.createDependency(dependent, td);
            }
        }
	}

	/**
	 * Get all the triggers relevant to this DML operation
	 *
	 * @param dd				The data dictionary
	 * @param td				The TableDescriptor
	 * @param changedColumnIds	If null, all columns being changed, otherwise array
	 *							of 1-based column ids for columns being changed
	 * @param includeTriggers	whether we allow trigger processing or not for
	 * 							this table
	 *
	 * @return	the constraint descriptor list
	 *
	 * @exception StandardException		Thrown on failure
	 */
    protected TriggerDescriptorList getAllRelevantTriggers
	(
		DataDictionary		dd,
		TableDescriptor		td,
		int[]				changedColumnIds,
		boolean 			includeTriggers
    )
		throws StandardException
	{
		if ( relevantTriggers !=  null ) { return relevantTriggers; }

        relevantTriggers =  new TriggerDescriptorList();

		if(!includeTriggers)
			return relevantTriggers;

		td.getAllRelevantTriggers( statementType, changedColumnIds, relevantTriggers );
		adjustDeferredFlag( relevantTriggers.size() > 0 );
		return relevantTriggers;
	}

	protected	void	adjustDeferredFlag( boolean adjustment )
	{
		if( !requiresDeferredProcessing ) { requiresDeferredProcessing = adjustment; }
	}

	/**
	 * Get all of our dependents due to a constraint.
	 *
	 * Makes the calling object (usually a Statement) dependent on all the constraints.
	 *
	 * @param dd				The data dictionary
	 * @param cdl				The constraint descriptor list
	 * @param dependent			Parent object that will depend on all the constraints
	 *							that we look up. If this argument is null, then we
	 *							use the default dependent (the statement being compiled).
	 *
	 * @exception StandardException		Thrown on failure
	 */
	private void createConstraintDependencies
	(
		DataDictionary				dd,
		ConstraintDescriptorList 	cdl,
		Dependent					dependent
	)
		throws StandardException
	{
		CompilerContext 			compilerContext = getCompilerContext();

		int cdlSize = cdl.size();
		for (int index = 0; index < cdlSize; index++)
		{
			ConstraintDescriptor cd = cdl.elementAt(index);

			/*
			** The dependent now depends on this constraint. 
			** the default dependent is the statement 
			** being compiled.
			*/
			if (dependent == null) 
			{ 
				compilerContext.createDependency(cd); 
			}
			else 
			{ 
				compilerContext.createDependency(dependent, cd); 
			}

			/*
			** We are also dependent on all referencing keys --
			** if one of them is deleted, we'll have to recompile.
			** Also, if there is a BULK_INSERT on the table
			** we are going to scan to validate the constraint,
			** the index number will change, so we'll add a
			** dependency on all tables we will scan.
			*/
			if (cd instanceof ReferencedKeyConstraintDescriptor)
			{	
				ConstraintDescriptorList fkcdl = dd.getActiveConstraintDescriptors
					( ((ReferencedKeyConstraintDescriptor)cd).getForeignKeyConstraints(ConstraintDescriptor.ENABLED) );
	
				int fklSize = fkcdl.size();
				for (int inner = 0; inner < fklSize; inner++)
				{
					ConstraintDescriptor fkcd = fkcdl.elementAt(inner);
					if (dependent == null) 
					{ 
						compilerContext.createDependency(fkcd); 
						compilerContext.createDependency(fkcd.getTableDescriptor()); 
					}
					else 
					{ 
						compilerContext.createDependency(dependent, fkcd); 
						compilerContext.createDependency(dependent, fkcd.getTableDescriptor()); 
					}
				}
			}
			else if (cd instanceof ForeignKeyConstraintDescriptor)
			{
				ForeignKeyConstraintDescriptor fkcd = (ForeignKeyConstraintDescriptor) cd;
				if (dependent == null) 
				{ 
					compilerContext.createDependency(fkcd.getReferencedConstraint().getTableDescriptor()); 
				}
				else
				{
					compilerContext.createDependency(dependent, 
									fkcd.getReferencedConstraint().getTableDescriptor()); 
				}
			}
		}
	}

	/**
	 * Get all the constraints relevant to this DML operation
	 *
	 * @param dd				The DataDictionary
	 * @param td				The TableDescriptor
	 * @param changedColumnIds	If null, all columns being changed, otherwise array
	 *							of 1-based column ids for columns being changed
	 *
	 * @return	the constraint descriptor list
	 *
	 * @exception StandardException		Thrown on failure
	 */
	protected ConstraintDescriptorList getAllRelevantConstraints
	(
		DataDictionary		dd, 
		TableDescriptor		td,
		int[]				changedColumnIds
    )
		throws StandardException
	{
		if ( relevantCdl != null ) { return relevantCdl; }

		boolean[]	needsDeferredProcessing = new boolean[1];
		relevantCdl = new ConstraintDescriptorList();

		needsDeferredProcessing[0] = requiresDeferredProcessing;
		td.getAllRelevantConstraints
            ( statementType, changedColumnIds,
			  needsDeferredProcessing, relevantCdl );

		adjustDeferredFlag( needsDeferredProcessing[0] );

		return relevantCdl;
	}

	/**
	 * Does this DML Node require deferred processing?
	 * Set to true if we have triggers or referential
	 * constraints that need deferred processing.
	 *
	 * @return true/false 
	 */
    boolean requiresDeferredProcessing()
	{
		return requiresDeferredProcessing;
	}

	/**
	  *	Parse a check constraint and turn it into a query tree.
	  *
	  *	@param	checkConstraintText	Text of CHECK CONSTRAINT.
	  * @param	td					The TableDescriptor for the table the the constraint is on.
	  *
	  *
	  * @return	The parsed check constraint as a query tree.
	  *
	  * @exception StandardException		Thrown on failure
	  */
	public	ValueNode	parseCheckConstraint
	(
		String				checkConstraintText,
		TableDescriptor		td
    )
		throws StandardException
	{
		Parser						p;
		ValueNode					checkTree;
		LanguageConnectionContext	lcc = getLanguageConnectionContext();

		/* Get a Statement to pass to the parser */

		/* We're all set up to parse. We have to build a compile SQL statement
		 * before we can parse - we just have a WHERE clause right now.
		 * So, we goober up a SELECT * FROM table WHERE checkDefs.
		 */
		String select = "SELECT * FROM " +
			            td.getQualifiedName() +
			            " WHERE " +
			            checkConstraintText;
		
		/*
		** Get a new compiler context, so the parsing of the select statement
		** doesn't mess up anything in the current context (it could clobber
		** the ParameterValueSet, for example).
		*/
		CompilerContext newCC = lcc.pushCompilerContext();

		p = newCC.getParser();
				
		/* Finally, we can call the parser */
		// Since this is always nested inside another SQL statement, so topLevel flag
		// should be false
		Visitable qt = p.parseStatement(select);
		if (SanityManager.DEBUG)
		{
			if (! (qt instanceof CursorNode))
			{
				SanityManager.THROWASSERT(
					"qt expected to be instanceof CursorNode, not " +
					qt.getClass().getName());
			}
			CursorNode cn = (CursorNode) qt;
			if (! (cn.getResultSetNode() instanceof SelectNode))
			{
				SanityManager.THROWASSERT(
					"cn.getResultSetNode() expected to be instanceof SelectNode, not " +
					cn.getResultSetNode().getClass().getName());
			}
		}

		checkTree = ((SelectNode) ((CursorNode) qt).getResultSetNode()).getWhereClause();

		lcc.popCompilerContext(newCC);

		return	checkTree;
	}


	/**
	  *	Generate the code to evaluate a tree of CHECK CONSTRAINTS.
	  *
	  *	@param	checkConstraints	Bound query tree of ANDed check constraints.
	  *	@param	ecb					Expression Class Builder
	  *
	  *
	  *
	  * @exception StandardException		Thrown on error
	  */
	public	void	generateCheckConstraints
	(
		ValueNode				checkConstraints,
		ExpressionClassBuilder	ecb,
		MethodBuilder			mb
    )
							throws StandardException
	{
		// for the check constraints, we generate an exprFun
		// that evaluates the expression of the clause
		// against the current row of the child's result.
		// if there are no check constraints, simply pass null
		// to optimize for run time performance.

   		// generate the function and initializer:
   		// Note: Boolean lets us return nulls (boolean would not)
   		// private Boolean exprN()
   		// {
   		//   return <<checkConstraints.generate(ps)>>;
   		// }
   		// static Method exprN = method pointer to exprN;

		// if there is no check constraint, we just want to pass null.
		if (checkConstraints == null)
		{
		   	mb.pushNull(ClassName.GeneratedMethod);
		}
		else
		{
			MethodBuilder	userExprFun = generateCheckConstraints(checkConstraints, ecb);

	   		// check constraint is used in the final result set 
			// as an access of the new static
   			// field holding a reference to this new method.
   			ecb.pushMethodReference(mb, userExprFun);
		}
	}

	/**
	  *	Generate a method to evaluate a tree of CHECK CONSTRAINTS.
	  *
	  *	@param	checkConstraints	Bound query tree of ANDed check constraints.
	  *	@param	ecb					Expression Class Builder
	  *
	  *
	  *
	  * @exception StandardException		Thrown on error
	  */
	public	MethodBuilder	generateCheckConstraints
	(
		ValueNode				checkConstraints,
		ExpressionClassBuilder	ecb
    )
		throws StandardException
	{
		// this sets up the method and the static field.
		// generates:
		// 	java.lang.Object userExprFun { }
		MethodBuilder userExprFun = ecb.newUserExprFun();
		
		// check constraint knows it is returning its value;
		
		/* generates:
		 *    return <checkExpress.generate(ecb)>;
		 * and adds it to userExprFun
		 */

		checkConstraints.generateExpression(ecb, userExprFun);
		userExprFun.methodReturn();
		
		// we are done modifying userExprFun, complete it.
		userExprFun.complete();

		return userExprFun;
	}

	/**
	  *	Generate the code to evaluate all of the generation clauses. If there
	  *	are generation clauses, this routine builds an Activation method which
	  *	evaluates the generation clauses and fills in the computed columns.
      *
      * @param rcl  describes the row of expressions to be put into the bas table
      * @param resultSetNumber  index of base table into array of ResultSets
      * @param isUpdate true if this is for an UPDATE statement
      * @param ecb code generation state variable
      * @param mb the method being generated
      *
	  * @exception StandardException		Thrown on error
	  */
	public	void	generateGenerationClauses
	(
        ResultColumnList        rcl,
        int                     resultSetNumber,
        boolean                 isUpdate,
		ExpressionClassBuilder	ecb,
		MethodBuilder			mb
    )
        throws StandardException
	{
        boolean hasGenerationClauses = false;

        for (ResultColumn rc : rcl)
		{
            // Generated columns should be populated after the base row because
            // the generation clauses may refer to base columns that have to be filled
            // in first.
            //
			if ( rc.hasGenerationClause() )
            {
                hasGenerationClauses = true;
                break;
            }
        }

		// we generate an exprFun
		// that evaluates the generation clauses
		// against the current row of the child's result.
		// if there are no generation clauses, simply pass null
		// to optimize for run time performance.

   		// generate the function and initializer:
   		// private Integer exprN()
   		// {
        //   ...
   		//   return 1 or NULL;
   		// }
   		// static Method exprN = method pointer to exprN;

		// if there are not generation clauses, we just want to pass null.
		if ( !hasGenerationClauses )
		{
		   	mb.pushNull(ClassName.GeneratedMethod);
		}
		else
		{
			MethodBuilder	userExprFun = generateGenerationClauses( rcl, resultSetNumber, isUpdate, ecb);

	   		// generation clause evaluation is used in the final result set 
			// as an access of the new static
   			// field holding a reference to this new method.
   			ecb.pushMethodReference(mb, userExprFun);
		}
	}

	/**
	  *	Generate a method to compute all of the generation clauses in a row.
      *
      * @param rcl  describes the row of expressions to be put into the bas table
      * @param rsNumber  index of base table into array of ResultSets
      * @param isUpdate true if this is for an UPDATE statement
      * @param ecb code generation state variable
      *
	  */
	private	MethodBuilder	generateGenerationClauses
	(
        ResultColumnList            rcl,
        int                                 rsNumber,
        boolean                         isUpdate,
		ExpressionClassBuilder	ecb
    )
		throws StandardException
	{
		// this sets up the method and the static field.
		// generates:
		// 	java.lang.Object userExprFun( ) { }
		MethodBuilder userExprFun = ecb.newUserExprFun();

        /* Push the the current row onto the stack. */
        userExprFun.pushThis();
        userExprFun.push( rsNumber );
        userExprFun.callMethod(VMOpcode.INVOKEVIRTUAL, ClassName.BaseActivation, "getCurrentRow", ClassName.Row, 1);

		// Loop through the result columns, computing generated columns
        // as we go. 
        int     size = rcl.size();
        int     startColumn = 0;
        // For UPDATEs, we only compute the updated value for the
        // column. The updated value lives in the second half of the row.
        // This means we ignore the first half of the row, which holds
        // the before-images of the columns.
        if ( isUpdate )
        {
            // throw away the last cell in the row, which is the row id
            startColumn = size - 1;
            startColumn = startColumn / 2;
        }
        for ( int i = startColumn; i < size; i++ )
        {
            ResultColumn rc = rcl.elementAt( i );

            if ( !rc.hasGenerationClause() ) { continue; }

            userExprFun.dup();       // instance (current row)
            userExprFun.push(i + 1); // arg1

            // poke our result set number into all column references in this generation expression
            // if we're an action of a MERGE statement. that is because the dummy SELECT was not
            // actually optimized so column references still need result set numbers
            if ( inMatchingClause() )
            {
                CollectNodesVisitor<ColumnReference> getCRs =
                    new CollectNodesVisitor<ColumnReference>( ColumnReference.class );
                rc.accept( getCRs );

                for ( ColumnReference cr : getCRs.getList() )
                {
                    cr.getSource().setResultSetNumber( rsNumber );
                }
            }

            rc.generateExpression(ecb, userExprFun);
            userExprFun.cast(ClassName.DataValueDescriptor);
                
            userExprFun.callMethod(VMOpcode.INVOKEINTERFACE, ClassName.Row, "setColumn", "void", 2);
        }

		/* generates:
		 *    return;
		 * And adds it to userExprFun
		 */
		userExprFun.methodReturn();
		
		// we are done modifying userExprFun, complete it.
		userExprFun.complete();

		return userExprFun;
	}

  /**
   * 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.
   *
   *
   * @exception StandardException         Thrown on failure
   */
    @Override
	public void optimizeStatement() throws StandardException
	{
        //
        // If this is the INSERT/UPDATE/DELETE action of a MERGE statement,
        // then we don't need to optimize the dummy driving result set, which
        // is never actually run.
        //
        // don't need to fully optimize the dummy SELECT, which is never actually run
        if ( !inMatchingClause() )
        {
            /* First optimize the query */
            super.optimizeStatement();
        }
        else if ( this instanceof UpdateNode )
        {
            //
            // However, for UPDATE actions of MERGE statements, we do preprocess the driving SELECT.
            // This is where the virtual column ids in CHECK constraints are re-mapped to
            // refer to column positions in the SELECT list rather than in the base table.
            //
            resultSet = resultSet.preprocess
                (
                 getCompilerContext().getNumTables(),
                 null,
                 (FromList) null
                 );
        }

		/* In language we always set it to row lock, it's up to store to
		 * upgrade it to table lock.  This makes sense for the default read
		 * committed isolation level and update lock.  For more detail, see
		 * Beetle 4133.
		 */
		lockMode = TransactionController.MODE_RECORD;
	}

	/**
	 * Get the list of indexes that must be updated by this DML statement.
	 * WARNING: As a side effect, it creates dependencies on those indexes.
	 *
	 * @param td	The table descriptor for the table being updated
	 * @param updatedColumns	The updated column list.  If not update, null
	 * @param colBitSet			a 1 based bit set of the columns in the list
	 *
	 * @exception StandardException		Thrown on error
	 */
	protected void getAffectedIndexes
	(
		TableDescriptor		td,
		ResultColumnList	updatedColumns,	
		FormatableBitSet				colBitSet
	)
					throws StandardException
	{
        ArrayList<ConglomerateDescriptor> conglomerates = new ArrayList<ConglomerateDescriptor>();

        DMLModStatementNode.getXAffectedIndexes(
                td, updatedColumns, colBitSet, conglomerates);

        markAffectedIndexes(conglomerates);
	}
	/**
	  *	Marks which indexes are affected by an UPDATE of the
	  *	desired shape.
	  *
	  *	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.
	  *
	  *	@param	updatedColumns	a list of updated columns
	  *	@param	colBitSet		OUT: evolving bitmap of affected columns
      * @param  conglomerates   OUT: list of affected indices
	  *
	  * @exception StandardException		Thrown on error
	  */
	static void getXAffectedIndexes
	(
		TableDescriptor		baseTable,
		ResultColumnList	updatedColumns,
        FormatableBitSet    colBitSet,
        List<ConglomerateDescriptor>                conglomerates
	)
		throws StandardException
	{
		ConglomerateDescriptor[]	cds = baseTable.getConglomerateDescriptors();

		/* we only get distinct conglomerate numbers.  If duplicate indexes
		 * share one conglomerate, we only return one number.
		 */
		long[] distinctConglomNums = new long[cds.length - 1];
		int distinctCount = 0;

		for (int index = 0; index < cds.length; index++)
		{
			ConglomerateDescriptor cd = cds[index];

			if (!cd.isIndex()) { continue; }

			/*
			** If this index doesn't contain any updated
			** columns, then we can skip it.
			*/
			if ((updatedColumns != null) &&
				(!updatedColumns.updateOverlaps(
					cd.getIndexDescriptor().baseColumnPositions())))
			{ continue; }

            if ( conglomerates != null )
			{
				int i;
				for (i = 0; i < distinctCount; i++)
				{
					if (distinctConglomNums[i] == cd.getConglomerateNumber())
						break;
				}
				if (i == distinctCount)		// first appearence
				{
					distinctConglomNums[distinctCount++] = cd.getConglomerateNumber();
                    conglomerates.add( cd );
				}
			}

			IndexRowGenerator ixd = cd.getIndexDescriptor();
			int[] cols = ixd.baseColumnPositions(); 

			if (colBitSet != null)
			{
				for (int i = 0; i < cols.length; i++)
				{
					colBitSet.set(cols[i]);
				}
			}	// end IF
		}		// end loop through conglomerates

	}

	protected	void	markAffectedIndexes
	(
        List<ConglomerateDescriptor> affectedConglomerates
    )
		throws StandardException
	{
		ConglomerateDescriptor	cd;
		int						indexCount = affectedConglomerates.size();
		CompilerContext			cc = getCompilerContext();

		indicesToMaintain = new IndexRowGenerator[ indexCount ];
		indexConglomerateNumbers = new long[ indexCount ];
		indexNames = new String[indexCount];

		for ( int ictr = 0; ictr < indexCount; ictr++ )
		{
            cd = affectedConglomerates.get( ictr );

			indicesToMaintain[ ictr ] = cd.getIndexDescriptor();
			indexConglomerateNumbers[ ictr ] = cd.getConglomerateNumber();
			indexNames[ictr] = 
				((cd.isConstraint()) ? null : cd.getConglomerateName());

			cc.createDependency(cd);
		}

	}


    String statementToString()
	{
		return "DML MOD";
	}

	/**
	 * Remap referenced columns in the cd to reflect the
	 * passed in row map.
	 *
	 * @param cd 		constraint descriptor
	 * @param rowMap	1 based row map 
	 */
	private int[] remapReferencedColumns(ConstraintDescriptor cd, int[] rowMap)
	{
		int[] oldCols = cd.getReferencedColumns();
		if (rowMap == null)
		{
			return oldCols;
		}

		int[] newCols = new int[oldCols.length];
		for (int i = 0; i<oldCols.length; i++)
		{
			newCols[i] = rowMap[oldCols[i]];
			if (SanityManager.DEBUG)
			{
				SanityManager.ASSERT(newCols[i] != 0, "attempt to map a column "+
					oldCols[i]+" which is not in our new column map.  Something is "+
					"wrong with the logic to do partial reads for an update stmt");
			}
		}
		return newCols;
	}

	/**
	 * Get a integer based row map from a bit set.
	 * 
	 * @param bitSet
	 * @param td 
	 * 
	 */ 
	private	int[] getRowMap(FormatableBitSet bitSet, TableDescriptor td)
		throws StandardException
	{
		if (bitSet == null)
		{
			return (int[])null;
		}

		int size = td.getMaxColumnID();
		int[] iArray = new int[size+1];
		int j = 1;
		for (int i = 1; i <= size; i++)
		{
			if (bitSet.get(i))
			{
				iArray[i] = j++;
			}
		}
		return iArray;
	}


    @Override
    void setRefActionInfo(long fkIndexConglomId,
								 int[]fkColArray, 
								 String parentResultSetId,
								 boolean dependentScan)
	{
		resultSet.setRefActionInfo(fkIndexConglomId,
								   fkColArray,
								   parentResultSetId,
								   dependentScan);
	}

	/**
	 * Normalize synonym column references to have the name of the base table. 
	 *
	 * @param rcl	           The result column list of the target table
	 * @param targetTableName  The target tablename
	 *
	 * @exception StandardException		Thrown on error
	 */
    void normalizeSynonymColumns(
    ResultColumnList    rcl, 
    TableName           targetTableName)
		throws StandardException
	{
		if (synonymTableName == null) 
            return;
		
		String synTableName = synonymTableName.getTableName();
		
        for (ResultColumn rc : rcl)
		{
            ColumnReference reference = rc.getReference();

			if ( reference != null )
			{
				String crTableName = reference.getTableName();
				if ( crTableName != null )
				{
					if ( synTableName.equals( crTableName ) )
					{
						reference.setQualifiedTableName( targetTableName );
					}
					else
					{
						throw StandardException.newException(
                                SQLState.LANG_TABLE_NAME_MISMATCH, 
                                synTableName, 
                                crTableName);
					}
				}
			}
		}
	}

	/**
	 * Prints the sub-nodes of this object.  See QueryTreeNode.java for
	 * how tree printing is supposed to work.
	 *
	 * @param depth		The depth of this node in the tree
	 */
    @Override
    void printSubNodes(int depth)
	{
		if (SanityManager.DEBUG)
		{
			super.printSubNodes(depth);

            if ( targetTableName != null )
            {
                printLabel(depth, "targetTableName: ");
                targetTableName.treePrint(depth + 1);
            }

			if (resultColumnList != null)
			{
				printLabel(depth, "resultColumnList: ");
				resultColumnList.treePrint(depth + 1);
			}
		}
	}

	/**
	 * Accept the visitor for all visitable children of this node.
	 * 
	 * @param v the visitor
	 *
	 * @exception StandardException on error
	 */
    @Override
	void acceptChildren(Visitor v)
		throws StandardException
	{
		super.acceptChildren(v);

		if (targetTableName != null)
		{
            targetTableName = (TableName) targetTableName.accept(v);
		}

        if (synonymTableName != null) {
            synonymTableName = (TableName) synonymTableName.accept(v);
        }
	}
}
