FIX: SQLOLEDB Resends Prepared Commands with Client Cursors

View products that this article applies to.

This article was previously published under Q238355

BUG #: 55798 (SQLBUG_70)

Expand all | Collapse all

SYMPTOMS

When using the SQLOLEDB provider with client side cursors and prepared statements, the performance is slower than with SQL Server 6.5 and ODBC. When tracing the SQL statements sent by the client application with SQL Server Profiler, a sequence of statements similar to the following can be observed:

SQL Server 7.0

sp_prepare @P1 output, N'@P1 varchar(40)', N'select au_fname, au_lname
   from pubs..authors where au_lname like @P1', 1 select @P1
sp_unprepare 1
sp_executesql N'select au_fname,au_lname from pubs..authors
   where au_lname like @P1', N'@P1 nvarchar(2)', N'M%'

SQL Server 6.5

create proc #oledbsa1(@P1 varchar(40)) as select au_fname,au_lname<BR/>
   from pubs..authors where au_lname like @P1
select au_fname,au_lname from pubs..authors where au_lname like 'M%'

Back to the top

CAUSE

As shown in the SQL trace, under these circumstances the SQLOLEDB provider first prepares the statement but sends it again to get the rows for the client side cursor.

Back to the top

WORKAROUND

To work around this problem, try either of the following:

Do not use prepared statements.

-or-
Use server based cursors.

Back to the top

STATUS

Microsoft has confirmed this to be a problem in SQL Server 7.0. This problem has been corrected in U.S. Service Pack 2 for Microsoft SQL Server 7.0. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

254561 (http://support.microsoft.com/kb/254561/ ) INF: How to Obtain Service Pack 2 for Microsoft SQL Server 7.0 and Microsoft Data Engine (MSDE) 1.0

For more information, contact your primary support provider.

Back to the top