Oracle性能调整的要点之SGA(1)(2)

SELECT size_for_estimate,buffers_for_estimate,estd_physical_read_factor,estd_phy
sical_reads FROM v$db_cache_advice WHERE NAME=’DEFAULT’ AND advice_status=’ON’ 
AND block_size=(SELECT Value FROM v$parameter WHERE NAME=’db_block_size’);
    estd_physical_read_factor<=1

SELECT NAME,value FROM v$sysstat WHERE NAME IN (’session logical reads’,'physic
al reads’,'physical reads direct’,'physical reads direct(lob)’);
    Cache hit ratio=1-(physical reads-physical reads direct-physical reads direct 
(lob))/session logical reads;
    Select 1-(phy.value-dir.value-lob.value)/log.value from v$sysstat log, v$syss
tat phy, v$sysstat dir, v$sysstat LOB where log.name=’session logical reads’ and 
phy.name=’physical reads’ and dir.name=’physical reads direct’ and lob.name=’
physical reads direct (lob)’;