Optimizing text file writing in VB 6.0

[tscpb]

I am completing the coding of a utility that reads data from a database and writes the returnset to a text file. The writing to the .txt file is performed by the client. The text file can range in size from 1 line to 20 million lines. When a file is less then 100K, the following code works fairly effieciently, however anything above moves very slow. Does anyone know how to optimize the writing of the output to a .txt file if the recordset count is greater then 100K?

Existing Code:

If Not RS.EOF Then
        If bInteractive Then frmMain.StatusBar.Panels(1).Text = "Writing data..."
        Set FSO = New FileSystemObject
        Set TxtStream = FSO.OpenTextFile(OutputFileName, ForWriting, True)
        'Write Column Headers
        'Column headers below in ""
        DataHeaders = "Field0" & "|" & "Field1" & "|" & "Field2" & "|" & "Field3" & "|" & "Field4 & "|" & "Field5" & "|" & "Field6" & "|" & "Field7" & "|" & "Field8" & "|" & "Field9" & "|" & "Field10" & "|" & "Field11" & "|" & "Field12" & "|" & "Field13" & "|" & "Field14"
        TxtStream.WriteLine DataHeaders & vbCrLf 
        j = 0
        k = 0
        While Not RS.EOF
            '    "Field0 - 14 represent variables                       
            Field0 = IIf(IsNull(RS.Fields(0)), "", RS.Fields(0))          
            Field1 = IIf(IsNull(RS.Fields(1)), "", RS.Fields(1))
            Field2 = IIf(IsNull(RS.Fields(2)), "", RS.Fields(2))
            Field3 = IIf(IsNull(RS.Fields(3)), "", RS.Fields(3))
            Field4 = IIf(IsNull(RS.Fields(4)), "", RS.Fields(4))
            Field5 = IIf(IsNull(RS.Fields(5)), "", RS.Fields(5))
            Field6 = IIf(IsNull(RS.Fields(6)), "", RS.Fields(6))
            Field7 = IIf(IsNull(RS.Fields(7)), "", RS.Fields(7))
            Field8 = IIf(IsNull((RS.Fields(8) & "")), "", (RS.Fields(8) & ""))
            Field9 = IIf(IsNull(RS.Fields(9)), "", RS.Fields(9))
            Field10 = IIf(IsNull(RS.Fields(10)), "", RS.Fields(10))
            Field11 = IIf(IsNull(RS.Fields(11)), "", RS.Fields(11))
            Field12 = IIf(IsNull(RS.Fields(12)), "", RS.Fields(12))
            Field13 = IIf(IsNull(RS.Fields(13)), "", RS.Fields(13))
            Field14 = IIf(IsNull(RS.Fields(14)), "", RS.Fields(14))

'Write Column Data
            Data = Field0 & "|" & Field1 & "|" & Field2 & "|" & Field3 & "|" & Field4 & "|" & Field5 & "|" & Field6 & "|" & Field7 & "|" & Field8 & "|" & Field9 & "|" & Field10 & "|" & Field11 & "|" & Field12 & "|" & Field13 & "|" & Field14
            
            Buffer = Buffer & Data
            
            j = j + 1
            k = k + 1
            If bInteractive Then
                If k = frmMain.ProgressBar.Max Then
                    k = 0
                    frmMain.ProgressBar.Value = 0
                    frmMain.StatusBar.Panels(4).Text = Format(j, "#,##0") & " of " & Format(lngRecCount, "#,##0")
                    TxtStream.WriteLine Buffer
                    Buffer = ""
                Else
                    Buffer = Buffer & vbCrLf
                    frmMain.ProgressBar.Value = frmMain.ProgressBar.Value + 1
                End If
            Else
                If k = 1000 Then
                    k = 0
                    TxtStream.WriteLine Buffer
                    Buffer = ""
                Else
                    Buffer = Buffer & vbCrLf
                End If
            End If
            
            RS.MoveNext
                                
            DoEvents
        
        Wend
        
        Buffer = Left(Buffer, Len(Buffer) - 2)    'Remove the trailing crlf
        TxtStream.WriteLine Buffer
        TxtStream.Close