Originally posted by grjohnson
I think a larger drawback would be if DMBC * Block_Size was not a multiple of the segment's EXTENT. Since a read CANNOT cross an extent's boundary. The DB would therfore perform additional reads. e.g table with 3 extents of 128K (total size 384K) with an default block size, on DB configured with an 8k block with 128 DBMC would still require 3 i/o's to perform a FTS. Each read, reading the MAXIMUM, in this case, of 128K, and not 1024K which'd be (DMBC * Block_Size )
Sure, but I don't consider this to be a "choosing the correct DB_BLOCK_SIZE" problem - it is "choosing the correct storage parameters" problem (ie segment storage sizing, uniform LMT extent sizing, whatever).