I'm a newbie, so please bear with me!

I've done some searching thru google on when database objects should be pinned in memory, and am coming up with mixed answers. I've read some articles which state that you should pin any large, frequently used objects in memory. Other articles state that pinning was used moreso in the earlier versions of Oracle (7 and below) in response to numerous ORA-04031 errors, which are not as much a factor in the newer versions. (I'm working with Oracle 8i and 9i if this makes any difference.)

To me, pinning large, frequently used objects does not seem to make sense since frequently used objects are more likely to remain in memory b/c they are highly used, but as I said, I'm a newbie and I'm probably overlooking something. Also, is there any rule of thumb to determine the size of a 'large' object?

I guess I'm wondering mostly about what the main benefits of pinning objects are, and how to determine if performance would improve from pinning. Any information is appreciated! Thanks!