Understanding DAO Recordset Types
The DAO library offers several different types of recordsets. When you assign a table or a query to a recordset by means of a Set statement, you specify the type of recordset that you want to use. Your choice has implications for the demands on system resources that your code will make, as well as for the ways that your code can use the recordset.
Your Set statement can take any of several forms. In each case, the OpenRecordset method is used, and it takes several arguments:
Source— This is the only required argument. It's a string, and is the name of the object that contains the records. The source is usually a table or an existing query, but it could also be a SQL statement that defines a query.
Type— There ...