Buffer Cache hit ratio and performance problem
600574May 24 2009 — edited May 25 2009Hi,
I have some performance problem in my application, I think it's due to swapping and oversized buffer cache.
My buffer cache hit ratio is going below 30% when I run certain large queries, where as it should be 90% and above, . I have arround 3.7 GB SGA and buffer cache 1.84 GB, shared pool is 1.17 GB, library cache is 111 MB. parse to execute ratio is 38%.
DB_BLOCK_BUFFERS value is 0.
What should be the correct size of the buffer cache for a SGA size 3.7 GB. This DB is running on UNIX and on oracle 10G.
Whats the relationship between oversized buffer cache swap file. How can oversize buffer cache results in swapping. please provide a link so I could read and understand more about this.
Thank you