OracleDataReader.Read taking too long for the first record

Question

Hi Guys
I am new to ODP.Net. This is my first time working with Oracle and ODP.Net. I wrote a small stored procedure which returns 25 rows and returns a sys_refcursor. I am capturing that in a OracleDataReader and trying to process the data. I use this in a while loop... the first Read is taking around 10 seconds and from the second on, it is pretty quick. Stored procedure performace is really good when I run it from the SQLPlus or data execute call from .Net. Both web server and database are in the same network, which is really good.
Any idea what's going on? Any links or articles ro any help will be greatly appreciated...
I am using Oracle 10g with ODP.net 10.2.0.2.20. and using .Net Framework 3.5 with Visual Studio 2008.
Here is the code I am using (it is really simple)
Private Sub FillSearchResults(ByVal DR As Oracle.DataAccess.Client.OracleDataReader)
Dim objSearch As OCPAFL.DAL.Search
Dim objList As New List(Of Parcel)
Try
'Walk through Projects
While DR.Read()
''''.... do the processing here
End While
Catch ex As Exception
Throw ex
End Try
End Sub
Thanks
Chandra

Answer 1

Hi,
I dont have any good ideas as to what may be causing it based on the limited information provided, but here's what I'd do to try to troubleshoot it further:
1) Enable client sqlnet tracing (level 16) with timestamps on, and/or ODP tracing, reproduce the complaint, and loook in the trace to see if you can find a gap in the timestamps to try to isolate where the time is being consumed. Is there one 10 second gap? Numerous 2 second gaps? etc. Is the client waiting on data from the server?
2) Enable 10046 trace on the database before executing the proc in the app and check the resulting database trace. Are binds occurring differently? Is anything occurring differently in the execution plan using ODP vs SQLPlus?
Oh, also, support for .NET 3.5 starts with 11.1.6.20 ODP, but I rather doubt that's causing the problem.
Hope it helps,
Greg