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【DM版本】:V8
【操作系统】：centos
【CPU】:x86_84
【问题描述】*：COMPRESS_MODE 设置成1或0，创建测试表，占用的空间大小一样，没感受到压缩作用。

SQL> show parameter COMPRESS_MODE;

LINEID     PARA_NAME     PARA_VALUE
---------- ------------- ----------
1          COMPRESS_MODE 0
SQL> drop table computers;
executed successfully
used time: 27.505(ms). Execute id is 746.
SQL> drop table computers_ys;
executed successfully
used time: 19.859(ms). Execute id is 747.
SQL>
SQL> show parameter COMPRESS_MODE;

LINEID     PARA_NAME     PARA_VALUE
---------- ------------- ----------
1          COMPRESS_MODE 0
create table computers
(
 comNo number(10)  constraint PK_comp primary key,
 compModel varchar2(64) constraint unique_comp unique,
 buyTime date,
 price number(12,2) constraint ch_price check(
 price>0 and price<=3000000),
 owner varchar2(32));

executed successfully
used time: 5.805(ms). Execute id is 749.
SQL> DECLARE
  i number := 0;
BEGIN
  for i in 1 .. 300000 loop
    insert into computers
      (comNo, compModel, buyTime, price, owner)
    values
      (i, '8' + i, to_date('' + sysdate, 'YYYY-MM'), i, 'zhangsan');
    --dbms_output.put_line(i);
  end loop;
  commit;
END;
11  12  13  14  /
DMSQL executed successfully
used time: 00:00:06.334. Execute id is 750.
alter system set 'COMPRESS_MODE' = 1 both;
DMSQL executed successfully
used time: 7.697(ms). Execute id is 751.
SQL> show parameter COMPRESS_MODE;

LINEID     PARA_NAME     PARA_VALUE
---------- ------------- ----------
1          COMPRESS_MODE 1
create table computers_ys
(
 comNo number(10)  constraint PK_comp2 primary key,
 compModel varchar2(64) constraint unique_comp2 unique,
 buyTime date,
 price number(12,2) constraint ch_price2 check(
 price>0 and price<=3000000),
 owner varchar2(32));

DECLARE
  i number := 0;
BEGIN
  for i in 1 .. 300000 loop
    insert into computers_ys
executed successfully
used time: 6.225(ms). Execute id is 753.
SQL>       (comNo, compModel, buyTime, price, owner)
    values
      (i, '8' + i, to_date('' + sysdate, 'YYYY-MM'), i, 'zhangsan');
    --dbms_output.put_line(i);
  end loop;
  commit;
END;
10  11  12  13  14  /
DMSQL executed successfully
used time: 00:00:06.904. Execute id is 754.
SELECT
S2.NAME AS 模式名,
S1.NAME AS 表名,
TABLE_USED_SPACE(S2.NAME,S1.NAME) * PAGE /1024.0/1024.0 AS "表占用空间(MB)"
FROM
SYSOBJECTS S1,
SYSOBJECTS S2
WHERE
S1.SCHID = S2.ID
AND S1."SUBTYPE$" = 'UTAB'
AND S2."TYPE$" = 'SCH'
ORDER BY
2   3   4   5   6   7   8   9   10  11  12  13  3 DESC;

LINEID     模式名 表名                      表占用空间(MB)
---------- --------- --------------------------- -------------------
1          SYD       COMPUTERS_YS                36.875
2          SYD       COMPUTERS                   36.875
3          SYS       AQ$_QUEUES                  0.625
4          SYSDBA    T1                          0.375
5          SYS       AQ$_QUEUE_TABLES            0.25
6          SYS       DBMS_LOCK_ALLOCATED         0.125
7          SYS       POLICIES                    0.125
8          SYS       POLICY_COLS                 0.125
9          SYS       POLICY_CONTEXTS             0.125
10         SYS       POLICY_GROUPS               0.125
11         SYSDBA    TEST                        0.125
12         SYS       REG$                        0.125
13         SYSDBA    TEST_TABLE                  0.125
14         SYS       DBMS_ALERT_INFO             0.125
15         SYSDBA    ##PLAN_TABLE                0
16         SYS       ##TMP_TBL_FOR_DBMS_LOB_CLOB 0
17         SYSDBA    ##HISTOGRAMS_TABLE          0
18         SYS       ##TMP_TBL_FOR_DBMS_LOB_BLOB 0

18 rows got

used time: 1.523(ms). Execute id is 755.
SQL>