How reliable is "buffer hit ratio" for a "object oriented database"?
Hello,
if have checked buffer hit ratio with:
SELECT 1-(a.value / (b.value + c.value))
"Hit Ratio"
FROM v$sysstat a, v$sysstat b, v$sysstat c
WHERE a.name = 'physical reads'
AND b.name = 'db block gets'
AND c.name = 'consistent gets';
and it response with:
Hit Ratio
----------
.995270693
I am really surprised now and cant believe such a good value. I thougt over it and guessed the ratio is positv weighted by our application running the same sql x times producing positiv hits.
For example if the user list orders from a customers, it gets
- 1 sql for customer data
if have checked buffer hit ratio with:
SELECT 1-(a.value / (b.value + c.value))
"Hit Ratio"
FROM v$sysstat a, v$sysstat b, v$sysstat c
WHERE a.name = 'physical reads'
AND b.name = 'db block gets'
AND c.name = 'consistent gets';
and it response with:
Hit Ratio
----------
.995270693
I am really surprised now and cant believe such a good value. I thougt over it and guessed the ratio is positv weighted by our application running the same sql x times producing positiv hits.
For example if the user list orders from a customers, it gets
- 1 sql for customer data
1