The MINEXTENTS storage parameter is subject to the following restrictions:
（11）MINEXTENTS is not applicable at the tablespace level.
（22）You cannot change the value of MINEXTENTS in an ALTER statement or for an object that resides in a locally managed tablespace.
3. MAXEXTENTS
This storage parameter is valid only for objects in dictionary-managed tablespaces. Specify the total number of extents, including the first, that Oracle can allocate for the object. The minimum value is 1 except for rollback segments, which always have a minimum of 2. The default value depends on your data block size.
Restriction on MAXEXTENTS
MAXEXTENTS is ignored for objects residing in a locally managed tablespace, unless the value of ALLOCATION_TYPE is USER for the tablespace in the DBA_TABLESPACES data dictionary view.
--该参数在local managed tablespace 是忽略的。
UNLIMITED
Specify UNLIMITED if you want extents to be allocated automatically as needed. Oracle recommends this setting as a way to minimize fragmentation.
Do not use this clause for rollback segments. Doing so allows the possibility that long-running rogue DML transactions will continue to create new extents until a disk is full.
Caution:
4. PCTINCREASE
（1）In locally managed tablespaces, Oracle Database uses the value of PCTINCREASE during segment creation to determine the initial segment size and ignores this parameter during subsequent space allocation.
（2）In dictionary-managed tablespaces, specify the percent by which the third and subsequent extents grow over the preceding extent. The default value is 50, meaning that each subsequent extent is 50% larger than the preceding extent. The minimum value is 0, meaning all extents after the first are the same size. The maximum value depends on your operating system. Oracle rounds the calculated size of each new extent to the nearest multiple of the data block size. If you change the value of the PCTINCREASE parameter by specifying it in an ALTER statement, then Oracle calculates the size of the next extent using this new value and the size of the most recently allocated extent.
Restriction on PCTINCREASE
You cannot specify PCTINCREASE for rollback segments. Rollback segments always have a PCTINCREASE value of 0.
5. FREELISTS
（1）In tablespaces with manual segment-space management, Oracle Database uses the FREELISTS storage parameter to improve performance of space management in OLTP systems by increasing the number of insert points in the segment.
（2）In tablespaces with automatic segment-space management, this parameter is ignored, because the database adapts to varying workload.
In tablespaces with manual segment-space management, for objects other than tablespaces and rollback segments, specify the number of free lists for each of the free list groups for the table, partition, cluster, or index. The default and minimum value for this parameter is 1, meaning that each free list group contains one free list. The maximum value of this parameter depends on the data block size. If you specify a FREELISTS value that is too large, then Oracle returns an error indicating the maximum value.
This clause is not valid or useful if you have specified the SECUREFILE parameter of LOB_parameters. If you specify both the SECUREFILE pa