What is Calulation for creating a Segment in dba_segment table

Question

Hi
i used the command create table t11 (c char(10)) storage (initial 50K next 10K minextents 8 maxextents 10)
as per the forumla it will create a Two Segment in dba_segment table but by output show three segments
output is
Segment_type Block_id Bytes Block Block
Table 217 65536 8
Table 225 65536 8
Table 233 65536 8
I don't understatnd why it create a three segment ?
Sunil

Answer 1

Hit enter too soon.
I notice on the OP that minextents was set to 8. As such if dictionary management was in use I would have expected that 8 extents would have been allocated.
Initial = 50K + 7 extents of 10K = 120K
3 extents of 8 blocks each allocated so I suspect that the tablespace block size is 8k and that auto-allocate is in use so 3 64k extents were assigned or it could be 3 uniform extents of 64k.
The OP should have included the Oracle verision and tablespace space management policy in use.
HTH -- Mark D Powell --