db_block_buffers

[grjohnson]

Nah, nah, that's cool. You've still got me curious.

I performed the following:

I create a new table t1 with the CACHE option. I inserted records into the table (168703 records), equating to 1137 Blocks. Remembering the BUFFER_CACHE is 768 Blocks.

Then I did a FTS on T1 and the number of blocks from the table in the buffer cache was 463.

Then I created another table (t2) WITH the NOCACHE OPTION

i.e. CREATE TABLE T2 NOCACHE AS SELECT * FROM t1;

same number of records and did a FTS. Only 17 Blocks in the CACHE.

Interesting... cause it seems I can't completly flush the buffer_cache with a cached table.


Also, a FTS on a CACHED table seems to load into the LRU end of the BUFFER_CACHE... i.e. from LRU towards the MRU (like left to right)... and not from MRU to the LRU (right to left)... this is wierd.

If I perform the

SELECT block#, objd from v$bh order by block# asc;

Would it be correct in assuming the highest number block# is at the LRU end of the buffer cache?