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

This article helps you resolve a problem that can occur when you run an Oracle linked server query.

Original product version:   SQL Server
Original KB number:   2295405


Consider the following scenario:

  • You install 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.


    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

Third-party information disclaimer

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.


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 the third-party linked server provider is loaded inside SQL Server process and it incorrectly modifies heap memory that does not belong to it. If the Heap Functions inside a process is unstable, for protection from data corruption, the process is automatically shut down by the OS. 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 the described issue.


To work around this issue, use one of the following methods:

  • Remove the comments symbol.
  • Replace the comments symbol with the comments symbol: /* */.

More information

Contact the third-party provider for information and fixes. For latest OLEDB provider version, see 64-bit Oracle Data Access Components (ODAC) Downloads.