Is it strange ?

Hi all,
i'm a beginerr DBA and I've encountered something strange tuning my DB Server.
When I executed this statement

SELECT (1-(SUM(GETMISSES)/SUM(COUNT)))*100    "Dictionary Cache Hit Ratio"
FROM V$ROWCACHE; the result was -3534,76363636364 !!!!
I think there is an error in the statement, but i've found it on a Oracle Manual !!
The "Dictionary cache" should be at least 90% for a DSS Sytem, so why i got this value ?

Thanks a lot to everyone!
Bye.

--
Munarin Mauro - DBA
VeniceCom S.r.l. - Internet Business Solutions
Via Vespucci 7, 30173 Venezia Mestre
Tel.041 612 767 - Fax 041 612 263
http://www.venicecom.it



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