SQL Server service crashes when you run an Oracle linked server query

Applies to: Microsoft SQL Server 2005 Enterprise EditionSQL Server 2008 EnterpriseSQL Server 2008 R2 Enterprise


Consider the following scenario:
  • You install Microsoft SQL Server on a computer that is running Windows Server.
  • You create a linked server for an Oracle database.
  • You enable the Allow inprocess option in the options dialog box for the linked server provider.
    Note By default, the option is not selected.
  • You run a linked server query using the OraOLEDB provider.
In this scenario, the SQL Server service crashes, and no results are returned for the query. Additionally, you may encounter the following issues:
  • You receive the following error message in the Windows system event log:

    The SQL Server (MSSQLSERVER) service terminated unexpectedly. It has done this 1 time(s).

  • A minidump file of the SQL Server process is generated with heap corruption, and you receive an exception message that resembles the following:
    In minidump.mdmp the assembly instruction at ntdll!RtlReportCriticalFailure+62 in C:\Windows\System32\ntdll.dll from Microsoft Corporation has caused an unknown exception (0xc0000374) on thread 235
    OR sometimes alternatively in errorlog can be seen another exception:
    SqlDumpExceptionHandler: Process 74 generated fatal exception c0000005 EXCEPTION_ACCESS_VIOLATION. SQL Server is terminating this process.
  • The stack of the minidump file contains third-party modules inside the Sqlserver.exe process. For example, the minidump file contains the following information in Oracle modules:

    Full Call Stack: Function Arg 1 Arg 2 Arg 3 Arg 4

    ntdll!RtlReportCriticalFailure+62 00000000`00000002 00000000`00000023 00000000`403cc8a2 00000000`00000003
    ntdll!RtlpReportHeapFailure+26 00000000`403c95f0 00000000`403d7a78 00000000`403d7ab0 00000000`4d200e30
    ntdll!RtlpHeapHandleError+12 00000000`04180000 00000000`00000000 00000000`00000000 00000000`00000000
    ntdll!RtlpLogHeapFailure+a4 00000000`403d7b40 00000000`04180000 00000000`403d7b50 00000000`00000008
    ntdll!RtlFreeHeap+1aa8f 00000000`00000020 00000000`403cd850 00000000`00000001 00000000`403d0024
    ole32!CoTaskMemFree+36 00000000`403d6b00 00000000`00000001 00000000`4d200e30 00000000`00000024
    OraOLEDButl11+1a5f 00000000`00000001 00000000`4d200e30 00000000`00000024 00000000`403d7ab8
    0x403d6b00 00000000`4d200e30 00000000`00000024 00000000`403d7ab8 00000000`24492843
    0x00000001 00000000`00000024 00000000`403d7ab8 00000000`24492843 00000000`403b8c00
    0x4d200e30 00000000`403d7ab8 00000000`24492843 00000000`403b8c00 00000000`403c95f0
    0x00000024 00000000`24492843 00000000`403b8c00 00000000`403c95f0 00000000`403ca610
    0x403d7ab8 00000000`403b8c00 00000000`403c95f0 00000000`403ca610 00000000`403ca610
    OraOLEDBrst11+12843 00000000`403c95f0 00000000`403ca610 00000000`403ca610 00000000`403c95f0
    0x403b8c00 00000000`403ca610 00000000`403ca610 00000000`403c95f0 00000000`244928b1
    0x403c95f0 00000000`403ca610 00000000`403c95f0 00000000`244928b1 00000000`403d7ab8
    0x403ca610 00000000`403c95f0 00000000`244928b1 00000000`403d7ab8 00000000`403c95f0
    0x403ca610 00000000`244928b1 00000000`403d7ab8 00000000`403c95f0 00000000`4966a260
    0x403c95f0 00000000`403d7ab8 00000000`403c95f0 00000000`4966a260 00000000`05cd21e0
    OraOLEDBrst11+128b1 00000000`403c95f0 00000000`4966a260 00000000`05cd21e0 00000000`00000000
    0x403d7ab8 00000000`4966a260 00000000`05cd21e0 00000000`00000000 00000000`2449ca03
    0x403c95f0 00000000`05cd21e0 00000000`00000000 00000000`2449ca03 00000000`4d200e30
    0x4966a260 00000000`00000000 00000000`2449ca03 00000000`4d200e30 00000000`00000001
    0x05cd21e0 00000000`2449ca03 00000000`4d200e30 00000000`00000001 00000000`05cd21e0


This issue occurs because the special characters "--" exist in the query to the Oracle linked server. These characters are used as a comment symbol.

The SQL Server process crashes because of the third-party linked server provider which is loaded inside SQL Server process. If the third-party linked server provider is enabled together with the Allow inprocess option, the SQL Server process crashes when this third-party linked server experiences internal problems.


To work around this issue, use one of the following methods:
  • Remove the comments symbol.
  • Replace  the comments symbol with the following comments symbol: 
    /* */

More Information

The following table provides more information about the products or tools that automatically check for this condition on your instance of SQL Server and on the versions of the SQL Server product against which the rule is evaluated.

Rule software Rule title Rule description Product versions against which the rule is evaluated
System Center Advisor SQL Server has third-party modules loaded within SQL Server process and can cause SQL Server to crash  In this SQL Server instance, advisor detected the presence of one or more third-party modules within SQL Server Process space. These can cause SQL Server process to crash. Refer this Knowledge Base article for more details.  Microsoft SQL Server 2008
Microsoft SQL Server 2008 R2
Please contact the third party provider for information and fixes. For latest OLEDB provider version, please visit: