From andreyb@elrontelesoft.com Wed, 08 Aug 2001 02:48:29 -0700 From: Andrey Bronfin Date: Wed, 08 Aug 2001 02:48:29 -0700 Subject: RE: negative value for buffer cache hit ratio Message-ID: MIME-Version: 1.0 Content-Type: text/plain Hello Jonathan ! Thanks for reply ! First , i love your site and may i recommend it to all the listers : http://www.jlcomp.demon.co.uk/#Index Second, yes , U are right : SQL> col HITS for 999,999,999,999,999,999 SQL> select sum(dbbget + conget - pread) hits from x$kcbwds 2 where inst_id = userenv('Instance'); HITS ------------------------ -2,959,172,014 It's 8.0.5. The DB has been up since March,2001 -----Original Message----- Sent: Tuesday, August 07, 2001 10:16 PM To: Multiple recipients of list ORACLE-L It is possible that after 4 months your stats have wrapped around the ( ? 64 bit ?) limit value for your platform. Check the actual values from v$sysstat to see if some of them have gone negative or appear to be 'counting backwards'. Jonathan Lewis Seminars on getting the best out of Oracle Last few places available for Sept 10th/11th See http://www.jlcomp.demon.co.uk/seminar.html -----Original Message----- To: Multiple recipients of list ORACLE-L Date: 07 August 2001 19:52 | |Dear gurus ! |I have a negative value for buffer cache hit ratio in my DB which is up for |some 4 months . |Any ideas why ? |Thanks in advance. | |SQL> SELECT (1 - (SUM(DECODE(a.name,'physical reads',value,0)) / | 2 (SUM(DECODE(a.name,'consistent gets',value,0)) + | 3 SUM(DECODE(a.name,'db block gets',value,0))))) * 100 "buffer cache hit |ratio" | 4 FROM v$sysstat a; | |buffer cache hit ratio |---------------------- | -52.99284 | |-- |Please see the official ORACLE-L FAQ: http://www.orafaq.com |-- |Author: Andrey Bronfin | INET: andreyb@elrontelesoft.com | |Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 |San Diego, California -- Public Internet access / Mailing Lists |-------------------------------------------------------------------- |To REMOVE yourself from this mailing list, send an E-Mail message |to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in |the message BODY, include a line containing: UNSUB ORACLE-L |(or the name of mailing list you want to be removed from). You may |also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Jonathan Lewis INET: jonathan@jlcomp.demon.co.uk Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). -- Please see the official ORACLE-L FAQ: http://www.orafaq.com -- Author: Andrey Bronfin INET: andreyb@elrontelesoft.com Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051 San Diego, California -- Public Internet access / Mailing Lists -------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru@fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).