I can see you're running Baan.
With more than 2000 tables for every company in Baan, and if extent size not configured properly the actual query crashing the engine will reads an enormous amount from sysextents.
SELECT dbsname, tabname, count(*) extents FROM sysextents WHERE
dbsname NOT IN
('sysmaster','HASHTEMP','SORTTEMP','sysutils','sys cdr','onpload') AND
tabname != 'TBLSpace' AND tabname[1,3] != 'sys' GROUP BY dbsname,
tabname ORDER BY extents DESC, dbsName, tabName
This query is started from Patrol (.....) . Disable this part of Patrol.
Use the column "nextns" from sysptnhdr from the sysmaster db joined with systabnames to find out the number of axternts per table/fragment.
Or shutdown Patrol alltogether.....