They are
1.initial
2.next
3.minextents
4.maxextents
5.pctincrease (percentage increase)
Note : The storage parameter which is applicable only to rollback segments is "optimal".
pct increase storage parameter is not applicable to rollback segments.
With the help of storage parameters, we can control the number of extents allocated for a segment as well as the sizes of the extent.
We can specify the storage parameter either at the time of tablespace creation or at the time of object creation.
From 9i, oracle recommands not to specify because oracle takes care of the allocation of extents and its sizes.
If we specify the storage parameters at tablespace creation as well as at object creation, oracle considers the storage parameters that are specified at object creation(oracle gives priority to the object level storage parameter).
SQL> create tablespace hrms_ts
datafile '/u01/app/oracle/oradata/hrms/hrms_ts01.dbf' size 100m
default storage(initial 100k
next 100k
minextents 2
pctincrease 50
maxextents 10);
SQL> create table emp1(empno number(10),ename varchar2(20),sal number(10,2))
storage(initial 200k
next 200k
minextents 2
pctincrease 50
maxextents 20);
Initial represents the size of the first extent.
next represents the size in bytes of the next extent(second extent).
pctincrease represents the size in bytes by which the third and subsequent extent over the preceding extent.
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