Report Studio performance when using BW cubes ?

[sanchoniathon]

Hello,

1- We use a bw cube in our package to develop our Report Studio reports in version 8.4
2- I run this report that runs in just 5 seconds.
3- I rerun the same report seconds later (with same parameter values and all) and it takes 1 minute to run.
4- I rerun the same report 2 minutes later and it takes just 5 seconds ...
5- I rerun the same report 5 minutes later or so and it takes aroudn 1 minute to execute ...

Usually the BW team here at the office is able to have a sort of trace of user is requesting what from a bw cube etc ...
But they tell me that this time there were no trace possible as for the process job was made this time on the Cognos server  ??

Anyone can help me understand what he might meant ?... Is he saying that sometimes the reports will run and it will be the Cognos server
which will do the job and other times it will be the BW server who will do the job ?
Do i need to set the report query propertie "PROCESSING" to "Database Only" ??

Thanks in advance for any valuable tips on this one !

[DustPanMan]

When does it run faster?  On the database or on Cognos?  What is likely happening is a caching issue.  If it is running quickly, it is likely cached. 

[sanchoniathon]

Hello DustPanMan,

1- I'm not sure what side it is running faster but the last time it ran fast the BW had kept a trace ... so i presume it runs faster when the BW server is doing the job ??

2- But the thing is that i would expect it to run faster AFTER the first time because of cache issues. But it runs slower on the 3rd time, it then runs faster the 3rd time, etc... It seems random.

3- ANY ADVICES ? Any seetings to set on the servers ?

Thanks !

[DustPanMan]

Try setting database only and see what happens...

[sanchoniathon]

Already did ... same little problem.

???

Thanks anyhow !