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IBM Cognos 10 Platform => Cognos 10 BI => Cognos Administration => Topic started by: StevenLunn on 14 Mar 2014 09:43:11 AM

Title: Settings for Packet Size
Post by: StevenLunn on 14 Mar 2014 09:43:11 AM
Hi,

From Cognos, when accessing a particular data source (Microsoft SQL     
Server OLE DB) and running reports where large volumes of rows are     
returned, many of our Cognos reports are slow.                         
                                                                       
If we take the Cognos SQL and run it against the data source directly   
the results come back a lot faster, usually within a couple of minutes.
                                                                       
This suggests that it is the transfer of data from the data source to   
Cognos, rather than the execution of SQL that is causing the           
bottleneck. Experimenting directly with the data source some more and   
again transferring the returned data to another system (but not Cognos)
the slowness was still there. However this was improved dramatically by
increasing the packet size to the largest allowed (32767 from default   
4096).                                                                 
                                                                       
So we were wondering if there was a packet size setting in Cognos that 
we could amend to increase the transfer size between the data source   
and Cognos which would improve the reports? It's been suggested that we
could try adding Packet Size=32767; to the end of the connection string
on the Cognos data source, but it appears we cant change this in any   
way - Edit Connection string settings don't show anywhere to modify     
this.                                                                   
                         
If anyone has any ideas would appreciate it.

Thanks,

Steve