I'm trying to execute two queries on a database asynchronously by using the
..NET 2.0 APM. I've created a test harness which executes two queries which
take at least ten seconds each. Using the APM I would've expected the page to
load in a little over ten seconds, but instead it takes over 30.

Here's my code for a single ASP.NET page with two gridviews on. Any pointers
as to where i may be going wrong would be appreciated:

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Handles Me.Load
Dim aResult As IAsyncResult = BeginReader()
Dim aResultTwo As IAsyncResult = BeginSecondReader()
Dim aTable As DataTable = EndReader(aResult)
GridView1.DataSource = aTable
GridView1.DataBind()
Dim aTableTwo As DataTable = EndReader(aResultTwo)
GridView2.DataSource = aTableTwo
GridView2.DataBind()
End Sub

Public Shared Function BeginReader() As IAsyncResult
Dim myConn As New SqlConnection("Data Source=(local);Initial
Catalog=MyDB;Persist Security Info=True;User
ID=test_user;Password=test_user;Async=True;")
Dim myCmd As New SqlCommand("WAITFOR DELAY '00:00:10'; SELECT TOP 10
* FROM tblUser", myConn)
myCmd.CommandType = CommandType.Text
myConn.Open()

Dim asResult As IAsyncResult = myCmd.BeginExecuteReader(Nothing,
myCmd)
Return asResult
End Function

Public Shared Function BeginSecondReader() As IAsyncResult
Dim myConn As New SqlConnection("Data Source=(local);Initial
Catalog=MyDB;Persist Security Info=True;User
ID=test_user;Password=test_user;Async=True;")
Dim myCmd As New SqlCommand("WAITFOR DELAY '00:00:10'; SELECT TOP 10
* FROM tblUser ORDER BY NEWID()", myConn)
myCmd.CommandType = CommandType.Text
myConn.Open()

Dim asResult As IAsyncResult = myCmd.BeginExecuteReader(Nothing,
myCmd)
Return asResult
End Function

Public Shared Function EndReader(ByRef asResult As IAsyncResult) As
DataTable
Dim RetTable As New DataTable
Dim myCmd As SqlCommand = CType(asResult.AsyncState, SqlCommand)
myCmd.EndExecuteReader(asResult)
myCmd.Connection.Close()
Dim myAdapter As SqlDataAdapter = New SqlDataAdapter(myCmd)
myAdapter.Fill(RetTable)
Return RetTable
End Function
--
=============
VB .NET Developer
http://www.rocketscience.uk.com
http://info.i-snapshot.com

that information, if not then still why?\

Asynchrously processing need only more total processing time but will as
there are more destinations save througput time, however as it has to go
thru one pipe it is still one after the other even as that are packages.

Cor

I am not sure how async processing works in ado.net, however I think that in
your case both queries are executed in sequence because they both belong to
same connection. Plus you get a first connection performance hit.
Try using two connections and fire each query on its own connection.

--
Miha Markic [MVP C#, INETA Country Leader for Slovenia]
RightHand .NET consulting & development www.rthand.com
Blog: http://cs.rthand.com/blogs/blog_with_righthand/

"JumpingMattFlash" <JumpingMattFlash (AT) discussions (DOT) microsoft.com> wrote in
message news:9D62FD00-63B2-438E-8359-8CC276F7B01A (AT) microsoft (DOT) com...

Right. MARS... did you enable Multiple Active Resultsets?

--
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William R. Vaughn
President and Founder Beta V Corporation
Author, Mentor, Dad, Grandpa
Microsoft MVP
(425) 556-9205 (Pacific time)
Hitchhiker’s Guide to Visual Studio and SQL Server (7th Edition)
__________________________________________________ __________________________________________
"Miha Markic" <miha at rthand com> wrote