according to Oracle, buffer_cache_size= db_blocks_buffer * db_block_size.


On my statspack report on 9i, Oracle had:

Buffer Cache: 712M Std Block Size: 8K

and if db_blocks_buffer is currently =0, how Oracle come up with 712m???? Please explain, and if I run the below query:

select a.value + b.value "logical_reads",
c.value "phys_reads",
round(100 * ((a.value+b.value)-c.value) /
(a.value+b.value))
"BUFFER HIT RATIO"
from v$sysstat a, v$sysstat b, v$sysstat c
where
a.statistic# = 38
and
b.statistic# = 39
and
c.statistic# = 40;


I got -85 on my ratio which is bad.