堆表（heap table）的存储方式：
验证：
1、创建table
SQL> conn scott/tiger
Connected.
SQL> create table t1
2 (a int,
3 b varchar2(4000) default rpad('*',4000,'*'),
4 c varchar2(3000) default rpad('*',3000,'*')
5 )
6 /
Table created.
SQL> desc t1
Name Null Type
----------------------------------------- -------- ----------------------------
A NUMBER(38)
B VARCHAR2(4000)
C VARCHAR2(3000)
2、插入数据
SQL> insert into t1(a) values (1);
1 rows created;
SQL> insert into t1(a) values (2);
1 rows created;
SQL> insert into t1(a) values (3);
1 rows created;
SQL> select a from t1;
A
----------
1
2
3
3、删除一行数据
SQL> delete from t1 where a=2;
1 row deleted.
SQL> select a from t1;
A
----------
1
3
4、再重新插入一行记录
SQL> insert into t1(a) values (4);
1 row created.
SQL> select a from t1;
A
----------
1
4
3
从以上可以看出，数据插入并不是按顺序插入，而是使用了原来被删除的那条记录的空间！