Block allocation within an extent !!

[cruser3]

DB_BLOCK_SIZE=4096

ALTER TABLE EMP DEALLOCATE UNUSED;
ANALYZE TABLE EMP COMPUTE STATISTICS;
ON SELECTING THE FOLLOWING FROM USER_TABLES FOR EMP GET:

PCT_FREE : 10
PCT_USED : 40
INI_TRANS : 1
MAX_TRANS : 255
INITIAL_EXTENT : 65536
NEXT_EXTENT :
MIN_EXTENTS : 1
MAX_EXTENTS : 2147483645
PCT_INCREASE :
FREELISTS : 1
FREELIST_GROUPS : 1
NUM_ROWS : 18
BLOCKS : 1
EMPTY_BLOCKS : 14
AVG_SPACE : 3217
CHAIN_CNT : 0
AVG_ROW_LEN : 39

QUESTION:

INITIAL_EXTENT : 65536
SO TOTAL BLOCKS: 65536/4096 = 16 BUT
(BLOCKS + : 1
EMPTY_BLOCKS) : 14
---------
15
SHOULD'NT THE TOTAL BE 16 BLOCKS OR IS A BLOCK USED FOR OTHER INFO. HEADERS ETC ? ANY EXPLN. TO CLARIFY THIS WILL BE GREAT !!

[abhaysk]

Read concepts guide, u will find there.

[stmontgo]

Nice question,

Allow me to defer to asktom

http://asktom.oracle.com/pls/ask/f?p...:163812348068,

regards

steve

[cruser3]

Thanks - should have looked there in the first place - thought of adding it here as this board seems to have DBA's with degrees of normalization from 1 -> Infinity performing mental exercises !!