Excel VBA Performance – 1 million rows – Delete rows containing a value, in less than 1 min

I’m providing the first answer as a reference

Others may find it useful, if there are no other options available

• Fastest way to achieve the result is not to use the Delete operation
• Out of 1 million records it removes 100,000 rows in an average of 33 seconds

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Sub DeleteRowsWithValuesNewSheet()  '100K records   10K to delete
                                    'Test 1:        2.40234375 sec
                                    'Test 2:        2.41796875 sec
                                    'Test 3:        2.40234375 sec
                                    '1M records     100K to delete
                                    'Test 1:        32.9140625 sec
                                    'Test 2:        33.1484375 sec
                                    'Test 3:        32.90625   sec
    Dim oldWs As Worksheet, newWs As Worksheet, rowHeights() As Long
    Dim wsName As String, t As Double, oldUsedRng As Range

    FastWB True:    t = Timer

    Set oldWs = Worksheets(1)
    wsName = oldWs.Name

    Set oldUsedRng = oldWs.Range("A1", GetMaxCell(oldWs.UsedRange))

    If oldUsedRng.Rows.Count > 1 Then                           'If sheet is not empty
        Set newWs = Sheets.Add(After:=oldWs)                    'Add new sheet
        With oldUsedRng
            .AutoFilter Field:=1, Criteria1:="<>Test String"
            .Copy                                               'Copy visible data
        End With
        With newWs.Cells
            .PasteSpecial xlPasteColumnWidths
            .PasteSpecial xlPasteAll                            'Paste data on new sheet
            .Cells(1, 1).Select                                 'Deselect paste area
            .Cells(1, 1).Copy                                   'Clear Clipboard
        End With
        oldWs.Delete                                            'Delete old sheet
        newWs.Name = wsName
    End If
    FastWB False:   InputBox "Duration: ", "Duration", Timer - t
End Sub

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At high level:

• It creates a new worksheet, and keeps a reference to the initial sheet
• AutoFilters column 1 on the searched text: .AutoFilter Field:=1, Criteria1:="<>Test String"
• Copies all (visible) data from initial sheet
• Pastes column widths, formats, and data to the new sheet
• Deletes initial sheet
• Renames the new sheet to the old sheet name

It uses the same helper functions posted in the question

The 99% of the duration is used by the AutoFilter

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There are a couple limitations I found so far, the first can be addressed:

1. If there are any hidden rows on the initial sheet, it unhides them

   • A separate function is needed to hide them back
   • Depending on implementation, it might significantly increase duration

2. VBA related:

   • It changes the Code Name of the sheet; other VBA referring to Sheet1 will be broken (if any)
   • It deletes all VBA code associated with the initial sheet (if any)

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A few notes about using large files like this:

• The binary format (.xlsb) reduce file size dramatically (from 137 Mb to 43 Mb)

• Unmanaged Conditional Formatting rules can cause exponential performance issues

  • The same for Comments, and Data validation

• Reading file or data from network is much slower than working with a locall file