FIX: ODBC Provider Throws "Integer divide by zero" Error When Selecting Numerous Large VARCHAR Fields (248417)
The information in this article applies to:
- Microsoft Data Access Components 2.1 SP2
This article was previously published under Q248417 SYMPTOMS When selecting several large VARCHAR fields that are less than 8 KB in size through the Microsoft OLE
DB Provider for ODBC, an 0xc0000094 "Integer division by zero" error occurs and
the application throws an access violation. Drastically reducing the number of
selected VARCHAR fields eliminates the problem, as does increasing the size of the
fields to something over 8 KB.
This problem occurs when using the
MDAC 2.1 SP2 version of the provider, namely the Msdasql.dll file version
2.10.4202, but does not occur with earlier versions. CAUSE If the rowset that is being generated by the SELECT statement contains numerous large VARCHAR fields, the calculation of the size of the bookmark table is not
done correctly and a value of zero is returned. This zero is then used when
attempting to divide up the buffer space allocated for the bookmark table into
bookmark entries. RESOLUTIONA supported hotfix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Only apply it to systems that are experiencing this specific problem. This hotfix may receive additional testing. Therefore, if you are not severely affected by this problem, we recommend that you wait for the next Microsoft Data Access Components service pack that contains this hotfix. To resolve this problem immediately, contact Microsoft Product Support Services to obtain the hotfix. For a complete list of Microsoft Product Support Services telephone numbers and information about support costs, visit the following Microsoft Web site: Note In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The usual support costs will apply to additional support questions and issues that do not qualify for the specific update in question.
The English version of this has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.
Date Time Version Size File name Platform
-------------------------------------------------------------
12/10/99 02.12.4810 277KB msdasql.dll
12/10/99 02.12.4810 10KB msdasqlr.dll
12/10/99 02.12.4810 62KB msdatl2.dll
12/10/99 02.12.4810 37KB msdatt.dll
Workaround Following are the three workarounds for this problem. - Use the previous version of the ODBC provider (MSDASQL)
from MDAC 2.1 SP1, which is version 2.10.3711.
- If the database you are targeting supports VARCHAR fields larger than 8 KB you can modify the table so that the size
of the VARCHAR fields exceed 8 KB.
NOTE: Microsoft SQL Server and Oracle do not support VARCHAR fields larger than 8 KB. - Reduce the number of large VARCHAR fields in the rowset.
STATUSMicrosoft has
confirmed that this is a bug in the Microsoft products that are listed at the
beginning of this article.
MORE INFORMATIONImportant You cannot install this hotfix on a computer that is currently running MDAC
2.1 SP1 GA (version 2.10.3711.11) or earlier. You must be using MDAC 2.1 SP2 GA
(version 2.10.4202) in order to use this hotfix. Since this hotfix resolves a
bug that is only found in the 2.10.4202 version of the ODBC provider, there
should be no reason to apply this hotfix to earlier releases. In
order to alleviate memory fragmentation problems, significant code changes were
made to the Msdatl2.dll file that this provider is linked with. If
this hotfix is installed on a computer that is running MDAC 2.1 SP1 GA
(2.10.3711) or earlier, other providers may fail to load and crashes or other
unexpected errors may occur. Please see the "References" section below for more
information. In addition, you must install all 4 files that are
included in the hotfix package. Manual Installation- Close or stop any applications or services that are using
any of the files listed above. This may include Internet Information Server
(IIS), Microsoft Transaction Server (MTS), Microsoft SQL Server, and any ADO or
OLE DB applications.
- Download the hotfix file (Largevarchar.exe) into a
temporary directory, and run it to extract the following files:
Msdasql.dll Msdasqlr.dll Msdatl2.dll Msdatt.dll - Locate and rename the current versions of these files, that
should be in the \Program Files\Common Files\System\OLE DB folder.
- Copy the hotfix files into the same location, and then
restart your services and applications.
Steps to Reproduce Behavior Copy the following code into a Visual Basic application; add a
reference to the Microsoft ActiveX Data Objects 2.1 Library; compile it; and
run it. Notice that an error is thrown when attempting to execute the MoveNext
method. Note that your connection string should be changed prior to executing
this code. Note You must change User ID=<username>
and password =<strong password> to the correct values before you run this
code. Make sure that User ID has the appropriate permissions to perform this
operation on the database.
Dim conn As New ADODB.Connection
Dim rs As New ADODB.Recordset
Dim DropTable As String, CreateTable As String, AppendTable1 As String, AppendTable2 As String
'DropTable = "Drop table LongFields" 'Not needed for first execution
CreateTable = "CREATE TABLE LongFields ([key] [int] IDENTITY (1, 1) NOT NULL ," & _
"[1] [varchar] (7000) NULL , [2] [varchar] (7000) NULL , [3] [varchar] (7000) NULL ," & _
"[4] [varchar] (7000) NULL , [5] [varchar] (7000) NULL , [6] [varchar] (7000) NULL ," & _
"[7] [varchar] (7000) NULL , [8] [varchar] (7000) NULL , [9] [varchar] (7000) NULL ," & _
"[10] [varchar] (7000) NULL , [11] [varchar] (7000) NULL , [12] [varchar] (7000) NULL ," & _
"[13] [varchar] (7000) NULL , [14] [varchar] (7000) NULL , [15] [varchar] (7000) NULL ," & _
"[16] [varchar] (7000) NULL , [17] [varchar] (7000) NULL , [18] [varchar] (7000) NULL ," & _
"[19] [varchar] (7000) NULL , [20] [varchar] (7000) NULL)"
AppendTable1 = "Insert into LongFields values ('abc', 'abc', 'abc', 'abc', 'abc'," & _
"'abc', 'abc', 'abc', 'abc', 'abc'," & _
"'abc', 'abc', 'abc', 'abc', 'abc'," & _
"'abc', 'abc', 'abc', 'abc', 'abc')"
AppendTable2 = "Insert into LongFields values ('xyz', 'xyz', 'xyz', 'xyz', 'xyz'," & _
"'xyz', 'xyz', 'xyz', 'xyz', 'xyz'," & _
"'xyz', 'xyz', 'xyz', 'xyz', 'xyz'," & _
"'xyz', 'xyz', 'xyz', 'xyz', 'xyz')"
conn.CursorLocation = adUseServer
conn.Open "DSN=Pubs;User Id=<username>;Password=<strong password>;Database=Pubs;"
'conn.Execute DropTable 'Not needed for first execution
conn.Execute CreateTable
conn.Execute AppendTable1
conn.Execute AppendTable2
rs.ActiveConnection = conn
rs.Properties("Hold Rows") = True
rs.CursorType = adOpenKeyset
rs.Open "select * from LongFields"
rs.MoveNext '<--- Code fails here
rs.Close
conn.Close
End Sub
REFERENCESFor additional information about the memory fragmentation
issue referenced above, click the article number below to view the article in
the Microsoft Knowledge Base: 230101 Data Queries Sporadically Return Empty Recordsets
Modification Type: | Minor | Last Reviewed: | 10/12/2005 |
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Keywords: | kbHotfixServer kbQFE kbBug kbDatabase kbfix kbOLEDB210fix kbProvider kbQFE KB248417 kbAudDeveloper |
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