BUG: Qualifying Table Name in Query Results in More I/O Op.

 Last reviewed: May 5, 1997
Article ID: Q96196

The information in this article applies to:
  • Microsoft SQL Server versions 4.2 and 4.2a for OS/2
  • Microsoft SQL Server, versions 4.21 and 4.21a
BUG# OS/2: 1586 (4.2) 
       NT:   97 (4.2)

SYMPTOMS

Fully qualifying a table name with a database name in a query results in more I/O operations and more query processing time than using a non-fully qualified table name.

Examples

Query 1 (table name not fully qualified): 

   update titles
   set titles.royalty = titles.royalty
   from titles

   Result Logical reads: 92
Query 2 (table name fully qualified): 

   update pubs..titles
   set titles.royalty = titles.royalty
   from titles

   Results Logical reads: 398

WORKAROUND

Use the table name without fully qualifying it with the database name. Alternatively, use fully qualified tablenames consistently throughout the query.

Example

   update pubs..titles
   set pubs..titles.royalty = pubs..titles.royalty
   from pubs..titles

STATUS

Microsoft has confirmed this to be a problem in SQL Server versions 4.2 and 4.2a for OS/2 and Microsoft SQL Server versions 4.21 and 4.21a. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

Additional query words:
Keywords : kbbug4.20 kbbug4.20a kbbug4.21 kbother SSrvServer SSrvWinNT
Version : 4.2 4.2a | 4.21 4.21a
Platform : OS/2 WINDOWS

THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY.

Last reviewed: May 5, 1997
© 1998 Microsoft Corporation. All rights reserved. Terms of Use.