Find the closest string value from array or sql table?

Public Class Distance

        ''' <summary>

        ''' Compute Levenshtein distance

        ''' </summary>

        ''' <param name="s">String 1</param>

        ''' <param name="t">String 2</param>

        ''' <returns>Distance between the two strings.

        ''' The larger the number, the bigger the difference.

        ''' </returns>

        Public Function LD(s As String, t As String) As Integer

            Dim n As Integer = s.Length
            'length of s
            Dim m As Integer = t.Length
            'length of t
            Dim d As Integer(,) = New Integer(n, m) {}
            ' matrix
            Dim cost As Integer
            ' cost
            ' Step 1

            If n = 0 Then
                Return m
            End If

            If m = 0 Then
                Return n
            End If

            ' Step 2

            Dim i As Integer = 0
            While i <= n


                d(i, 0) = System.Math.Max(System.Threading.Interlocked.Increment(i), i - 1)
            End While

            Dim j As Integer = 0
            While j <= m


                d(0, j) = System.Math.Max(System.Threading.Interlocked.Increment(j), j - 1)
            End While

            ' Step 3

            For h As Integer = 1 To n

                'Step 4

                For f As Integer = 1 To m

                    ' Step 5

                    cost = (If(t.Substring(f - 1, 1) = s.Substring(h - 1, 1), 0, 1))

                    ' Step 6


                    d(h, f) = System.Math.Min(System.Math.Min(d(h - 1, f) + 1, d(h, f - 1) + 1), d(h - 1, f - 1) + cost)

                Next
            Next


            ' Step 7


            Return d(n, m)

        End Function

    End Class