这段代码会留下垃圾吗? 光有new,没有 nothing ,没有sub new() 也没有Sub fanalize().....?

Public Class ClsDBOperation
Shared Function DBOperate(ByVal SQLString As String) As DataTable
Try
Dim CONN As String
CONN = "Provider=Microsoft.Jet.OLEDB.4.0;Password="""";User ID=Admin;Data Source=" + Application.StartupPath + "\data\SMBus.mdb"
Dim oleconn As New OleDb.OleDbConnection(CONN)
Dim cmd As OleDb.OleDbCommand = New OleDb.OleDbCommand(SQLString, oleconn)
cmd.CommandType = CommandType.Text
Dim sTokens() As String
sTokens = SQLString.Split(" ")
If Strings.InStr("INSERT,DELETE,UPDATE", sTokens(0).ToUpper) Then
If oleconn.State <> ConnectionState.Open Then
oleconn.Open() '打开数据库连接
End If
cmd.ExecuteNonQuery() '执行SQL语句
If oleconn.State <> ConnectionState.Closed Then
oleconn.Close() '关闭数据库连接
End If
'If sTokens(0).ToUpper = "INSERT" Then
' MsgBox("插入记录成功")
' End If
' If sTokens(0).ToUpper = "DELETE" Then
' MsgBox("删除记录成功")
' End If
' If sTokens(0).ToUpper = "UPDATE" Then
' MsgBox("更新记录成功")
' End If
Return Nothing
Else
Dim ObjectdsDataSet As New DataSet()
Dim adapter As New OleDb.OleDbDataAdapter()
adapter.TableMappings.Add("Table", "TEMP")
adapter.SelectCommand = cmd
If oleconn.State <> ConnectionState.Open Then
oleconn.Open() '打开数据库连接
End If
cmd.ExecuteNonQuery() '执行SQL语句
If oleconn.State <> ConnectionState.Closed Then
oleconn.Close() '关闭数据库连接
End If
adapter.Fill(ObjectdsDataSet) '填充数据集
Return ObjectdsDataSet.Tables("TEMP")
End If
Catch
MsgBox(Err.Description)
End Try
Return Nothing
End Function
End Class