Hi ,
In following function Compare(), I have a serious performance issue when I update a DataRow column. And I am unable to trace out the reason. Please do help me to get rid of this.

Where the problem is? (from compare(), the below line of code creates performance issue.)
adoRow2.Item("Diff") = intDiff 'Problem in this line,execution is fast when i comment this line.

How did I found the problem exists in that line?
I commented that particulat line and executed the code run very fast.

Private Sub Compare()

Dim adoRow1 As DataRow
Dim adoRow2 As DataRow
Dim adoRows() As DataRow
Dim intDiff As Integer
Dim intNew As Integer
Dim intOld As Integer
Dim intChanged As Integer
Dim blnIsNull As Boolean

Try

Select Case m_enuDataType
Case 0, 2

m_adoTable1.DefaultView.Sort ="DistItemNo, DistId, InvoiceNo, InvoiceLineNo,InvoiceDate"
m_adoTable2.DefaultView.Sort ="DistItemNo, DistId, InvoiceNo, InvoiceLineNo,InvoiceDate"

End Select

For Each adoRow1 In m_adoTable1.Rows

Select Case m_enuDataType

Case 0, 2
adoRows = m_adoTable2.Select("InvoiceLineNo = '" + PrepWhereValue(adoRow1.Item("InvoiceLineNo").ToString)
+ "'" + " AND InvoiceNo = '" + PrepWhereValue(adoRow1.Item("InvoiceNo").ToString)
+ "'" + " AND InvoiceDate = '" + PrepWhereValue(adoRow1.Item("InvoiceDate").ToString)
+ "'" + " AND OriginalDistId = '" + PrepWhereValue(adoRow1.Item ("DistId").ToString) + "'")

' If a matching row was found then compare the data in the rows.
If adoRows.GetUpperBound(0) = 0 Then

adoRow2 = adoRows(0)
intDiff = 0

blnIsNull = adoRow1.IsNull("SalesmanName")
If blnIsNull <> adoRow2.IsNull("SalesmanName") OrElse (Not blnIsNull AndAlso adoRow1.Item("SalesmanName").ToString <> adoRow2.Item("SalesmanName").ToString) Then intDiff += 1048576
blnIsNull = adoRow1.IsNull("SalesTerritoryNo")
If blnIsNull <> adoRow2.IsNull("SalesTerritoryNo") OrElse (Not blnIsNull AndAlso adoRow1.Item("SalesTerritoryNo").ToString <> adoRow2.Item("SalesTerritoryNo").ToString) Then intDiff += 2097152
blnIsNull = adoRow1.IsNull("SalesmanNo")
If blnIsNull <> adoRow2.IsNull("SalesmanNo") OrElse (Not blnIsNull AndAlso adoRow1.Item("SalesmanNo").ToString <> adoRow2.Item ("SalesmanNo").ToString) Then intDiff += 4194304

adoRow1.Item("Diff") = intDiff
adoRow2.Item("Diff") = intDiff 'Problem in this line,execution is fast when i comment this line.

If intDiff <> 0 Then intChanged += 1

ElseIf adoRows.GetUpperBound(0) = -1 Then

adoRow1.Item(

"Diff") = 100000000000000000

intOld += 1

Else

adoRow1.Item("Diff") = 0

For Each adoRow2 In adoRows
adoRow2.Item("Diff") = 0
Next '<< For Each adoRow2 In adoRows

End If '<< If adoRows.GetUpperBound(0) = 0 Then

End Select '<< Select Case m_enuDataType

Select Case m_enuDataType

Case 0, 2

For Each adoRow2 In m_adoTable2.Select("Diff=-1")
adoRow2.Item("Diff") = 100000000000000000

intNew += 1

Next '<< For Each adoRow2 In m_adoTable2.Select("Diff=-1")

End Select '<< Select Case m_enuDataType

If Not m_blnCancel Then

m_adoTable1.DefaultView.Sort ="Diff Desc"

m_adoTable2.DefaultView.Sort ="Diff Desc"
' End the loading of the data and fire an event to indicate that the loading of data is done.

End If '<< If Not m_blnCancel Then

Catch errException As ThreadAbortException

Catch errException As Exception

Throw errException

Finally
' If canceled then the tables will not be used by the calling GUI and should be disposed.

If Not m_adoTable1 Is Nothing Then m_adoTable1.Dispose()
If Not m_adoTable2 Is Nothing Then m_adoTable2.Dispose()

End If '<< If Not m_blnDone Then

End Try

End Sub

Private Function PrepWhereValue(ByVal v_strValue As String) As String

Try

If Not v_strValue Is Nothing Then Return v_strValue.Replace("'", "''")

Catch ex As Exception
Throw ex
End Try
End Function