time consumption for a report

hi experts,

I have written a code for taking debtors list for SD.I have used bkpf,bseg,bsid,bsad for this ALv report. When i run this report it is taking 4 minutes.I fear that it may take more than that in future.So what can i do for this .Bseg is a cluster table thats the reason for it .But how to access it.

regards,

mani