As far as I know, there is only one thing that actually results in BADSTATS, and that's an absence of any single block reads in the time period. (But there may be other oddities that could be version dependent - like multiblock read times being faster than single block read times).
What do you get from select * from sys.aux_stats$
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Metalink says that we have BADSTATS when:
=> start the collection again when the workload is relevant.
Tried with interval 5 min,15 min, 1h, 2h, 8h, and I get only BADSTATS. Tried auto(interval)and manual(start/stop) mode, always BADSTATS.
I'll try with an interval > 8h, but, meanwhile, any suggestion is welcome.
Regards, Dimitre Radoulov