access vba的执行效率太低，怎样才能改善？

要从一个100万行的表里成对提取搜索的数据，用for循环时，执行1000次要近2个小时才能执行完毕，能改善吗？谢谢！

代码如下：

Sub aa()
Dim i As Integer
Dim sqlstr As String
Dim mydb As Database
Dim myds As Recordset, bb As Recordset
Dim NotInList As String
Dim fld As Field
Dim sql As String
DoCmd.SetWarnings False
start = Now()

For i = 1 To 1000

sql = "insert  into ccc select * from (select top 1 id,字段1,字段3,字段5  from a where 字段8 = 1 And 字段9 = 1 union select top 1 id,字段1,字段3,字段5  from a  where id>(select top 1 id from a where 字段8=1 and 字段9=1) and 字段1=(select top 1 字段1 from a where  字段8=1 and 字段9=1) and 字段9=0)"

DoCmd.RunSQL sql

DoCmd.RunSQL "delete  from A where exists(select * from ccc where cc.id=A.id)"

Next i

DoCmd.SetWarnings True

endtime = Now()

MsgBox start & "开始，" & endtime & "结束。" & "已经完成，用时" & Hour(endtime) - Hour(start) & "小时" & Minute(endtime) - Minute(start) & "分" & Second(endtime) - Second(start) & "秒"


End Sub