Advanced: Requires expert coding, interoperability, and multiuser skills.
This article applies only to a Microsoft Access database (.mdb).
- You can use Regedit.exe to edit the Windows Registry and change the MaxLocksPerFile value permanently.
- You can use the SetOption method of the DBEngine object to change the MaxLocksPerFile value temporarily in code.
- If the error occurs when you run an action query, you can modify the query and set its UseTransaction property to No.
Method 1: Changing MaxLocksPerFile in the Windows RegistryWARNING: If you use Registry Editor incorrectly, you may cause serious problems that may require you to reinstall your operating system. Microsoft cannot guarantee that you can solve problems that result from using Registry Editor incorrectly. Use Registry Editor at your own risk.
Use Registry Editor to increase the MaxLocksPerFile value under the following key:
To do so, right-click the MaxLocksPerFile value, click Modify, click the Decimal option, increase the Value Data from 9500 to some higher value, and then click OK.
Note that this method changes the Windows Registry setting for all applications that use the Microsoft Jet database engine version 4.0.
Method 2: Using SetOption to Change MaxLocksPerFile TemporarilyNOTE: The sample code in this article uses Microsoft Data Access Objects. For this code to run properly, you must reference the Microsoft DAO 3.6 Object Library. To do so, click References on the Tools menu in the Visual Basic Editor, and make sure that the Microsoft DAO 3.6 Object Library check box is selected.
Microsoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements. The SetOption method temporarily overrides values for the Microsoft Jet database engine keys in the Windows Registry. The new value remains in effect until you change it again, or until the DBEngine object is closed.
NOTE: Changes made to the MaxLocksPerFile setting using the SetOption method will only be available through the current session of Data Access Objects (DAO). Queries run through the Microsoft Access user interface, will still use the settings within the registry.
The following code sample sets MaxLocksPerFile to 200,000 before executing an update operation inside a transaction:
On Error GoTo LargeUpdate_Error
Dim db As DAO.Database, ws As DAO.Workspace
' Set MaxLocksPerFile.
DBEngine.SetOption dbMaxLocksPerFile, 200000
Set db = CurrentDb
Set ws = Workspaces(0)
' Perform the update.
db.Execute "UPDATE BigTable SET Field1 = 'Updated Field'", _
MsgBox Err & " " & Error
MsgBox "Operation Failed - Update Canceled"
Method 3: Setting the UseTransaction Property in an Action QueryIf a stored action query causes the error, you can set its UseTransaction property to No. Note that if you do this, you will not able to roll back your changes if there is a problem or an error while the query is executing:
- Open the query in Design view.
- On the View menu, click Properties.
- Click an empty space in the upper half of the query window to display the Query Properties dialog box.
- Set the UseTransaction property to No.
- Save the query and close it.
Steps to Reproduce BehaviorThe following example uses a Visual Basic procedure to create a table with 10,000 records in it, and then modifies the table in order to cause the error message:
- Open the sample database Northwind.mdb.
- Create a module and type the following procedure:
Dim db As Database, rs As Recordset
Dim iCounter As Integer, strChar As String
Set db = CurrentDb
db.Execute "CREATE TABLE BigTable (ID LONG, Field1 TEXT(255), " & _
"Field2 TEXT(255), Field3 TEXT(255), Field4 TEXT(255))", _
Set rs = db.OpenRecordset("BigTable", dbOpenDynaset)
iCounter = 0
strChar = String(255, " ")
While iCounter <= 10000
rs!ID = iCounter
rs!Field1 = strChar
rs!Field2 = strChar
rs!Field3 = strChar
rs!Field4 = strChar
iCounter = iCounter + 1
- To run the procedure, type the following line in the Immediate window, and then press ENTER:
The procedure creates a table called BigTable with 10,000 records in it.
- Save the module as Module1 and close it.
- Open the BigTable table in Design view.
- Change the FieldSize property of Field4 to 253.
- Save the table. Click Yes when you are prompted that some data may be lost. Note that, after a while, you receive the following error messages:Microsoft Access can't change the data type.
There isn't enough disk space or memory.Errors were encountered during the save operation. Data types were not changed. Properties were not updated.
For more information about customizing registry settings for the Jet database engine, click Microsoft Access Help on the Help menu, type Customizing Windows Registry settings for Microsoft Jet in the Office Assistant or the Answer Wizard, and then click Search to view the topic.
For more information about the UseTransaction property, click Microsoft Access Help on the Help menu, type UseTransaction property in the Office Assistant or the Answer Wizard, and then click Search to view the topic.
Article ID: 209940 - Last Review: Jun 23, 2005 - Revision: 1