ID: Q161329
The information in this article applies to:
IMPORTANT: This article contains information about editing the registry. Before you edit the registry, you should first make a backup copy of the registry files (System.dat and User.dat). Both are hidden files in the Windows folder.
Advanced: Requires expert coding, interoperability, and multiuser skills.
When you perform an operation on a table, you may receive the following error message if the operation creates a large number of page locks:
There isn't enough disk space or memory.
If you run an action query on a large table, you may receive this error
message:
There isn't enough disk space or memory to undo the data changes this
action query is about to make.
Portions of this article assume that you are familiar with Visual Basic for
Applications and with creating Microsoft Access applications using the
programming tools provided with Microsoft Access. For more information
about Visual Basic for Applications, please refer to the "Building
Applications with Microsoft Access 97" manual.
The page locks required for the transaction exceed the MaxLocksPerFile value, which defaults to 9500 locks. The MaxLocksPerFile setting is stored in the Windows Registry.
There are several ways to work around this behavior:
WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows 95. Microsoft cannot guarantee that problems resulting from the incorrect use of Registry Editor can be solved. Use Registry Editor at your own risk.
For information about how to edit the registry, view the Changing Keys And Values online Help topic in Registry Editor (Regedit.exe). Note that you should make a backup copy of the registry files (System.dat and User.dat) before you edit the registry.
Use Registry Editor to increase the MaxLocksPerFile value under the following key:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\3.5\Engines\Jet 3.5
Note that this method changes the Windows Registry setting for all
applications that use the Microsoft Jet database engine version 3.5.
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 DAO
(Data Access Objects). 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:
Sub LargeUpdate()
On Error GoTo LargeUpdate_Error
Dim db As Database, ws As Workspace
' Set MaxLocksPerFile.
DBEngine.SetOption dbMaxLocksPerFile, 200000
Set db = CurrentDb
Set ws = Workspaces(0)
' Perform the update.
ws.BeginTrans
db.Execute "UPDATE LargeTable SET Field1 = 'Updated Field'", _
dbFailOnError
ws.CommitTrans
db.Close
MsgBox "Done!"
Exit Sub
LargeUpdate_Error:
MsgBox Err & " " & Error
ws.Rollback
MsgBox "Operation Failed - Update Canceled"
Exit Sub
End Sub
If 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:
1. Open the query in Design view.
2. On the View menu, click Properties.
3. Click an empty space in the upper half of the query window to display
the Query Properties dialog box.
4. Set the UseTransaction property to No.
5. Save the query and close it.
STATUS
This behavior is by design.
The MaxLocksPerFile setting in the Windows Registry prevents transactions in the Microsoft Jet database engine from exceeding a specified value. If a transaction attempts to create locks in excess of the MaxLocksPerFile value, then the transaction is split into two or more parts and partially committed. This feature was added to Microsoft Access 97 to prevent Netware 3.1 server crashes when the specified Netware lock limit was exceeded, and to improve performance with both Netware and Windows NT.
The 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:
1. Open the sample database Northwind.mdb.
2. Create a module and type the following procedure.
NOTE: In the following sample code, an underscore (_) at the end of a
line is used as a line-continuation character. Remove the underscore
from the end of the line when re-creating this code.
Sub CreateBigTable()
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))", _
dbFailOnError
Set rs = db.OpenRecordset("BigTable", dbOpenDynaset)
iCounter = 0
strChar = String(255, " ")
While iCounter <= 10000
rs.AddNew
rs!ID = iCounter
rs!Field1 = strChar
rs!Field2 = strChar
rs!Field3 = strChar
rs!Field4 = strChar
rs.Update
iCounter = iCounter + 1
Wend
MsgBox "Done!"
End Sub
3. To run the procedure, type the following line in the Debug window,
and then press ENTER.
CreateBigTable
The procedure creates a table called BigTable with 10,000 records in it.
4. Save the module as Module1 and close it.
5. Open the BigTable table in Design view.
6. Change the FieldSize property of Field4 to 253.
7. Save the table. Click OK when you are prompted that some data may be
lost. Note that after a time 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 the SetOption method, search the Help Index for "SetOption method."
For more information about customizing Windows Registry settings for Microsoft Access 97, search the Help Index for "Registry."
For more information about the UseTransaction property, search the Help Index for "UseTransaction property."
Additional query words: MaxLocksPerFile Netware
Keywords : kberrmsg kbnetwork PgmObj
Version : 97
Platform : WINDOWS
Hardware : x86
Issue type : kbprb
Last Reviewed: November 21, 1998