Symptoms
This article describes the following about this hotfix release:The issues that are fixed by this hotfix packageThe prerequisites for applying the hotfix packageInformation about whether you must restart the computer after you install the hotfix packageInformation about whether the hotfix package is replaced by any other hotfix packageInformation about whether you must make any registry changes The files that are contained in the hotfix package
Resolution
Consider the following scenario. You create a query that uses the UNION ALL operator more than 255 times. You submit this query from a client application to Microsoft SQL Server 2000. In this scenario, a stack overflow exception may occur, and then SQL Server unexpectedly closes. When this problem occurs, the client application receives the following error message:

Server: Msg 8621, Severity 17, State 1, Line 1 Internal Query Processor Error: The query processor ran out of stack space during query optimization. Additionally, the following error is written to the SQL Server error log:

Date Time spid52 Date Time Stack Overflow Dump not possible – Exception c00000fd E at 0×00000000005A8C70
Date Time spid52 Address=5a8c70 Exception Code = c00000fd
Date Time spid52 <the query statement (only part of the statement will be saved here due to length consideration>
Date Time spid52
Date Time spid52 TotalPhysicalMemory = 2139881472, AvailablePhysicalMemory = 1585553408
Date Time spid52 AvailableVirtualMemory = 7677010944000, AvailablePagingFile = 3594182656 On computers that run on the IA-64 architecture, the client application may receive the following error message:

[Microsoft][ODBC SQL Server Driver][DBNETLIB]ConnectionCheckForData (CheckforData()).
Server: Msg 11, Severity 16, State 1, Line 0 General Network Error. Connection broken Finally, the following error is written to the SQL Server event log:
Event type: Error
Event source: Service Control Manager
Event catalog: None
Event ID: 7034
Date: Date
Time: Date
User: N/A
Computer: ComputerName
Description: The MSSQLSERVER service terminated unexpectedly. It has done this 1 time(s). For a list of all publicly released SQL Server 2000 Post-Service Pack 3a hotfixes, see the following article in the Microsoft Knowledge Base:
810185?(http://support.microsoft.com/kb/810185/) SQL Server 2000 hotfix update for SQL Server 2000 Service Pack 3 and 3a