DB_BLOCK_SIZE
The size of single-block I/O requests. This parameter is also used in combination with multiblock parameters to determine multiblock I/O request size.
OS block size
Determines I/O size for redo log and archive log operations.
Maximum OS I/O size
Places an upper bound on the size of a single I/O request.
DB_FILE_MULTIBLOCK_READ_COUNT
The maximum I/O size for full table scans is computed by multiplying this parameter with DB_BLOCK_SIZE. (the upper value is subject to operating system limits). If this value is not set explicitly (or is set to 0), the default value corresponds to the maximum I/O size that can be efficiently performed and is platform-dependent.
SORT_AREA_SIZE
Determines I/O sizes and concurrency for sort operations.
HASH_AREA_SIZE
Determines the I/O size for hash operations.