BUG: Qualifying Table Name in Query Results in More I/O Op. (96196)

The information in this article applies to:

Microsoft SQL Server 4.2x

This article was previously published under Q96196

BUG# 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 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.

Modification Type:	Minor	Last Reviewed:	2/14/2005
Keywords:	kbother KB96196