FIX: Performance Decreases When the Source MDB File of Linked Access Table Is Open (293470)

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new, empty Access 2000 database named Child.mdb.
2. Open the Child.mdb file in Access, and add a linked table that connects to the Access Northwind sample database Customers table. For clarity, name the newly linked table "Linked_Customers".
3. Create a new Visual Basic 6.0 project. Form1 is created by default.
4. Add a reference to Microsoft ActiveX Data Objects 2.x.
5. Add a command button (cmdTest) to Form1.
6. Add the following code to the cmdTest_Click() event of Form1:

   Dim adoRS As ADODB.Recordset
   Dim sngTM As Single
   Dim adoCN As New ADODB.Connection
   
   adoCN.Open "Provider=Microsoft.Jet.OLEDB.4.0;" & _
      	 "Data Source=<full path and file name for Child.mdb"
   Set adoRS = New ADODB.Recordset
   sngTM = Timer
   adoRS.Open "SELECT * FROM LINKED_CUSTOMERS", _
       	adoCN, adOpenForwardOnly, adLockReadOnly, adCmdText
   adoRS.MoveFirst
   MsgBox "Elapsed Time = " & Timer - sngTM
   adoRS.Close
   Set adoRS = Nothing
   adoCN.Close
   Set adoCN = Nothing
   					

7. Change the Data Source property of the connection string to the Child.mdb path.
8. Run the Visual Basic project, and click the command button to execute the code. Note the elapsed time.
9. On a second workstation that has the appropriate version of Access installed, open the Northwind sample database.
10. Click the command button again on the default form of the Visual Basic project that is running on the first workstation. Notice that the elapsed time is significantly greater than it was the first time.
11. Close the instance of the Northwind sample database that is running on the second workstation.
12. Stop the execution of the Visual Basic project that is running on the first workstation.
13. Change the connection string in the sample code as follows:

    "Driver={Microsoft Access Driver (*.mdb)};" & _
            "DBQ=Child.mdb;DefaultDIR=<path to Child.mdb>"
    					

14. Repeat steps 8 through 10. You may notice similar behavior with this second connection string that uses the ODBC Driver. However, the performance decrease is slightly less than that observed with the OLE DB connection string.