Buffer_pool keep vs cache

Question

Hi,
i've a 11.2 database.
I want to reduce Logical Reads of a table that has only 300 records and 5 blocks.
This table is used many times in full scan.
I know that the keep is a defined pool and the cache use the buffer cache default pool.
It preferred to put it in buffer keep or use the table cache option?
tnx

Answer 1

In general, a small table that is used a lot will automagically be kept in the buffer cache, so you don't have to do anything.
When you might consider doing something is if you have lots of thrashing in the buffer, so things are getting kicked out and having to be read back in, and you already have a large buffer. But even there, simply reducing logical reads may have a consequent effect of reducing the thrashing, even if it is simply because of fewer read consistent copies being created in the buffer. So in nearly all cases with SGA size at least in the ballpark, tune the sql first. The small table is likely to be the least of your worries. In general, better to let Oracle work out what's going on in the default buffer, rather than taking away some and giving to the keep buffer.
If you see this table being read into PGA (like a lot of direct reads), that might be a different issue.