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In oracle11g, when each table is initially created, no extents are assigned to this object by default.

When data is inserted for the first time, the corresponding section is assigned.

The corresponding control parameter is deferred_segment_creation=true

If you want to keep properties consistent with earlier versions, you can set this parameter value to flase

Alter system set deferred_segment_creation=false scope=both

In subsequent new tables, extents are assigned by default.

If the parameter value is set to true, even if a specific storage parameter is specified when the table is created to obtain the initial section size, the corresponding section is not allocated.

Eg:

Create table A_ALLOCAT_EXTENT

(

Userno NUMBER

Username VARCHAR2 (20 CHAR)

)

Tablespace USERS

Pctfree 10

Initrans 1

Maxtrans 255

Storage

(

Initial 64K

Next 1M

Minextents 1

Maxextents unlimited

);

SQL > select * from user_extents t where t.segment_name = 'Aging ALCATROCATALCATIC extension'

No rows selected

After setting the parameter value to false, you need to add sections to the table that does not have an assigned section.

Get the name of the table without partition:

Select table_name from user_tables

Minus

Select segment_name from user_segments

Then execute the partition statement to allocate:

Alter table A_ALLOCAT_EXTENT allocate extent (size 8K);-- size is defined by itself.

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