For a old version of BW system with Oracle 11G, not sure how much your system is loaded.
However, you can always try to optimize resource available. If your memory is less, you need to add swap space and monitor it's usage.
Check for BW specific parameters.
1431798 - Oracle 11.2.0: Database Parameter Settings
180605 - Oracle database parameter settings for BW
1013912 - FAQ: Oracle BW performance
Divyanshu
