Microsoft KB Archive/126011

FIX: SQL Server 4.21a Service Pack 2 Fixlist

Article ID: Q126011
Creation Date: 12-FEB-1995
Revision Date: 30-APR-1997 '
The information in this article applies to:

Microsoft SQL Server, version 4.21a

The following is a list of fixes that have been made in SQL Server Service Pack 2. SQL Server Service Pack 2 is now available from your primary support provider. For more information, contact your primary support provider.

Please note that workarounds have been provided for your information only. It is not necessary to implement these workarounds if you have the updated software.

LIST OF PROBLEMS CORRECTED IN SERVICE PACK 2

FIX: Broken Connection Does Not Terminate Blocked SPID
FIX: Dropped Net Session Not Detected During Long Query
FIX: Conversion Errors to VAX Floating Point

FIX: Broken Connection Does Not Terminate Blocked SPID

ARTICLE ID: \[\[..\/\|Q\]\] BUG# NT: 932 (4.2)

SYMPTOMS

An unexpectedly large number of client connections to SQL Server may be observed using the sp_who command or performance monitor. Many of the clients shown by sp_who have rebooted or otherwise terminated their client applications. sp_who will show these clients to be blocked on one or more other client processes.

CAUSE

If a client connection is blocked by a lock held by another process and the client's connection to SQL server is abnormally broken (for example, network problems, client GP fault, or client reboot), the spid used by that client will not be freed until the blocking process releases its locks.

WORKAROUND

Clients should be sure to terminate their connection to SQL Server. Applications should cancel long running queries and, if necessary, explicitly close connections to SQL Server. This will tend to discourage users from rebooting or terminating applications taking an extended period of time to process SQL commands.

FIX: Dropped Net Session Not Detected During Long Query

ARTICLE ID: \[\[..\/\|Q\]\] BUG# NT: 966 (4.21)

SYMPTOMS

A query can continue to run on SQL Server even after the client reboots and the network session has dropped. The query will acquire whatever type of locks are appropriate for the query type, which in some cases can block other users. Unless it becomes blocked on another connection's lock, the query will terminate when it has run to completion or when it needs to send results back to the nonexistent client. The query can usually be terminated with the Transact-SQL KILL command.

CAUSE

If a client is running a long query that does not return results for a while, then the net session is dropped because the client reboots, the query can continue to run. An example of this type of query would be:

   SELECT COUNT(*) FROM LARGETABLE

If the query became blocked on another connection's lock, this could also prevent it from returning results. If in this state, the client running the query reboots, the query will continue to run even though its network session is terminated. This is caused by SQL Server not noticing the network session termination. Whenever the query begins to send results back to the nonexistent client, SQL Server will notice the network session is gone and terminate the query. WORKAROUND

This problem only happens infrequently, as two fairly rare simultaneous events must occur to reproduce it.

A long-running query that does not return results.
The same client running the query must abruptly terminate in an uncontrolled fashion, rather than logging out or canceling the query with dbcancel().

In cases where this happens, the workaround is to use the Transact-SQL KILL command to terminate the query. A well-designed application should always allow users to cancel a query at any point during execution. These applications will generally not see this problem. FIX: Conversion Errors to VAX Floating Point

ARTICLE ID: \[\[..\/\|Q\]\] BUG# NT: 959 (4.2)

SYMPTOMS

VAX clients may experience conversion errors when selecting very large float values from Microsoft SQL Server.

Additional query words:
Keywords : SSrvWinNT
Version : 4.21a 4.21a.sp2
Platform : WINDOWS
Issue type : kbref

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