IDS buffer reuse query

Ive been looking at trying to analyse our IDS buffer effectiveness, in terms of page reuse by object. The query: select a.dbsname , a.tabname , round(sum(c.reusecnt) / count(*),2) as avg_reuse , count(*) as num_buffs from systabnames a , sysptnext b , sysbufhdr c where c.pagenum between b.pe_phys and b.pe_phys + b.pe_size - 1 and a.partnum = b.pe_partnum group by 1,2 order by 4,1,2 seems to give the number of pages of each object in the buffer, and the average number of times each buffer is reused. onstat -p simply gives this percentage for the whole of the buffer, not by object. The query takes a few seconds to run, but can be quite revealing. However, I d like to get a breakdown by page type. Principally, Id like to be able to see the reuse rate of non-leaf index pages against leaf pages. The obvious place to get this seems to be from is syspaghdr, as the pg_flags column has the page type. onstat -B seems to be able to get this data quickly, but querying syspaghdr seems to take ages, as there is a row for every page in the instance (how does it do this? weve got a smallish system and to hold this data, would take over 1Gbyte of storage). Is there any table in the sysmaster database that holds the same information but just for the pages in the IDS buffer? syspaghdr doesnt seem to be indexed, as any join to it takes forever. onstat -B gets the data I want very quickly, but I dont know how it does it. Thanks Martyn Hodgson martyn.hodgson@eaglestar.co.uk