table with keep as buffer pool see much more physical reads than the number of blocks in the table

Hi, everyone, the oracle I use is 10.2.0.2 on HPUX IA64

Our job ran very slow and from AWR report I can see that a table named ATTRIBUTE_VALUE
consumes most of the physical IO (Physical read was more than 2.5M), as I know the blocks the table has is only 0.3M(block size is 8K), so I created a keep buffer and set the buffer pool of ATTRIBUTE_VALUE to "keep buffer". I was doing this to hope that once ATTRIBUTE_VALUE is read into the keep buffer, it will never be paged out so there the physical read will not exceed 0.3M (the blocks the table has). I already set the size of the keep buffer large enough (4G) to hold all the blocks.

But after that change, ATTRIBUTE_VALUE was still read physically much more times than 0.3M (about 1.6M). Shouldn't it be only 0.3M if the table was "kept" in the buffer?

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