Cognos report performance and cache

Question

I am working on Cognos 8, one of my report take roughly 1 minute to run but sometime 20 seconds as it loads from cache. Now for few needs I want to prove that report ran from cache for second time, how can I prove that? Is the performance is logged some where?

Answer 1

Cognos 8 uses old 32-bit CQM engine.
The cache of this engine is very primitive:

• Cache only works in same session.
• Only works if the query is identical.
• By defualt it cache the last 5 queries.
  

So based on limitation I wrote above you can do the following:

• Run the report in different session (different browser or user or user).
• Change any value in the prompt for different value.
  

This will ensure the report is not running from cache.

if you want to trace performance of queries, then using DB to capture the queries is the most efficient way. The alternative would be activating Congos ipf trace:
Cognos 8 report performance issues