1.试验前提
SQL> select * from v$version;
BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
PL/SQL Release 11.2.0.3.0 - Production
CORE 11.2.0.3.0 Production
TNS for Linux: Version 11.2.0.3.0 - Production
NLSRTL Version 11.2.0.3.0 - Production
SQL> select FORCE_LOGGING,SUPPLEMENTAL_LOG_DATA_PK,SUPPLEMENTAL_LOG_DATA_UI,
2 SUPPLEMENTAL_LOG_DATA_MIN from v$database;
FOR SUP SUP SUPPLEME
--- --- --- --------
NO NO NO NO
SQL> conn / as sysdba
Connected.
SQL> archive log list;
Database log mode Archive Mode
Automatic archival Enabled
Archive destination /opt/oracle/oradata/archivelog/chf
Oldest online log sequence 1879
Next log sequence to archive 1881
Current log sequence 1881
SQL> select count(*) from t_xifenfei_move;
COUNT(*)
----------
7432085
SQL> select bytes/1024/1024 from user_segments where segment_name='T_XIFENFEI_MOVE';
BYTES/1024/1024
---------------
832
从上面信息可以看到数据库处于归档模式，强制日志和辅助日志为开启，试验测试表t_xifenfei_move有7432085条记录，占用硬盘空间832M
2.常规CAST
SQL> alter system flush buffer_cache;
System altered.
SQL> alter system flush shared_pool;
System altered.
SQL> SET TIMING ON
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 100028
undo change vector size 16172
Elapsed: 00:00:00.06
SQL> create table chf.t_xifenfei_move_CAST tablespace users
2 as
3 select * from chf.t_xifenfei_move;
Table created.
Elapsed: 00:01:58.10
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 873150548
undo change vector size 131384
Elapsed: 00:00:00.01
SQL> select 873150548-100028 "redo size" from dual;
redo size
----------
873050520
SQL> select 131384-16172 "undo size" from dual;
undo size
----------
115212
通过这个可以得出结论，产生redo为873050520，undo为115212
3.普通INSERT
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:00.06
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.01
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 732
undo change vector size 136
Elapsed: 00:00:00.18
SQL> CREATE TABLE t_xifenfei_move_INSERT
2 AS
3 SELECT * FROM T_XIFENFEI_MOVE WHERE 1=0;
Table created.
Elapsed: 00:00:00.32
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 22712
undo change vector size 6512
Elapsed: 00:00:00.02
SQL> INSERT INTO t_xifenfei_move_INSERT
2 SELECT * FROM T_XIFENFEI_MOVE;
7432085 rows created.
Elapsed: 00:01:59.47
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 862261580
undo change vector size 27980508
--redo
SQL> select 22712-732 "create redo size" from dual;
create redo size
----------------
21980
SQL> select 862261580-22712 "insert redo size" from dual;
insert redo size
----------------
862238868
--undo
SQL> select 6512-136 "create undo size" from dual;
create undo size
----------------
6376
SQL> select 27980508-6512 "insert undo size" from dual;
insert undo size
----------------
27973996
通过这个可以得出CREATE TABLE 过程中产生redo:21980,undo:6376,而INSERT 过程中产生的redo:862238868,undo:27973996,整个过程总的产生redo:862260848(862238868+21980),undo:27980372(27973996+6376)
4.INSERT+APPEND
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:25.19
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.04
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 732
undo change vector size 136
Elapsed: 00:00:00.05
SQL> create table chf.t_xifenfei_move_INSERT_A tablespace users
2 as
3 select * from chf.t_xifenfei_move where 1=0;
Table created.
Elapsed: 00:00:00.18
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 21892
undo change vector size 6308
Elapsed: 00:00:00.00
SQL> INSERT /*+ append */INTO t_xifenfei_move_INSERT_A
2 SELECT * FROM T_XIFENFEI_MOVE;
7432085 rows created.
Elapsed: 00:02:26.37
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 872792032
undo change vector size 87764
--redo
SQL> select 21892-732 "create redo size" from dual;
create redo size
----------------
21160
SQL> select 872792032-21892 "insert redo size" from dual;
insert redo size
----------------
872770140
--undo
SQL> select 6308-136 "create undo size" from dual;
create undo size
----------------
6172
SQL> select 87764-6308 "insert undo size" from dual;
insert undo size
----------------
81456
这个过程可以得到结论,create 表的过程产生的redo:21160,undo:6172;insert 表的过程redo:872770140,undo:81456;整个过程产生的redo:872791300(21160+872770140),undo:87628(6172+81456)
5.INSERT+NOLOGGING
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:02.21
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.06
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 780
undo change vector size 136
Elapsed: 00:00:00.06
SQL> create table chf.t_xifenfei_move_INSERT_N tablespace users
2 as
3 select * from chf.t_xifenfei_move where 1=0;
Table created.
Elapsed: 00:00:00.22
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 22056
undo change vector size 6308
Elapsed: 00:00:00.00
SQL> INSERT /*+ NOLOGGING */INTO t_xifenfei_move_INSERT_N
2 SELECT * FROM T_XIFENFEI_MOVE;
7432085 rows created.
Elapsed: 00:02:30.33
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 862123984
undo change vector size 27982876
--redo
SQL> select 22056-780 "create redo size" from dual;
create redo size
----------------
21276
SQL> select 862123984-22056 "insert redo size" from dual;
insert redo size
----------------
862101928
--undo
SQL> select 6308-136 "create undo size" from dual;
create undo size
----------------
6172
SQL> select 27982876-6308 "insert undo size" from dual;
insert undo size
----------------
27976568
这个试验过程得出,create table得到redo:21276,undo:6172,insert table 得到redo:862101928,undo:27976568,整个过程redo:862123204,undo:27982740(27976568+6172)
6.INSERT+NOLOGGING(TABLE)
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:23.68
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.04
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 800
undo change vector size 136
Elapsed: 00:00:00.18
SQL> create table chf.t_xifenfei_move_INSERT_N_new nologging tablespace users
2 as
3 select * from chf.t_xifenfei_move where 1=0;
Table created.
Elapsed: 00:00:00.71
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 23296
undo change vector size 6756
Elapsed: 00:00:00.00
SQL> INSERT INTO t_xifenfei_move_INSERT_N_new
2 SELECT * FROM T_XIFENFEI_MOVE;
7432085 rows created.
Elapsed: 00:02:37.51
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 862031304
undo change vector size 27982776
SQL> select 23296-800 "create redo size" from dual;
create redo size
----------------
22496
SQL> select 862031304-23296 "insert redo size" from dual;
insert redo size
----------------
862008008
SQL> select 6756-136 "create undo size" from dual;
create undo size
----------------
6620
SQL> select 27982776-6756 "insert undo size" from dual;
insert undo size
----------------
27976020
通过该试验得出,create table 产生redo:22496,undo:6620;insert into 产生redo:862008008,undo:27976020;整个过程产生redo:862030504(22496+862008008),undo:27982640(6620+27976020)
7.APPEND+NOLOGGING(TABLE)
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:23.59
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.05
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 780
undo change vector size 136
Elapsed: 00:00:00.04
SQL> create table chf.t_xifenfei_move_INSERT_NA nologging tablespace users
2 as
3 select * from chf.t_xifenfei_move where 1=0;
Table created.
Elapsed: 00:00:00.42
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 22000
undo change vector size 6308
Elapsed: 00:00:00.00
SQL> INSERT /*+APPEND */ INTO t_xifenfei_move_INSERT_NA
2 SELECT * FROM T_XIFENFEI_MOVE;
7432085 rows created.
Elapsed: 00:01:08.92
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 602352
undo change vector size 82756
--redo
SQL> select 22000-780 "create redo size" from dual;
create redo size
----------------
21220
SQL> select 602352-22000 "insert redo size" from dual;
insert redo size
----------------
580352
--undo
SQL> select 6308-136 "create undo size" from dual;
create undo size
----------------
6172
SQL> select 82756-6308 "insert undo size" from dual;
insert undo size
----------------
76448
在这个试验中，create table产生redo:21220,undo:6172,insert into产生redo:580352,undo:76448;整个过程产生的redo:601572(
21220+580352),undo:82620(6172+76448)
8.CAST+NOLOGGING(TABLE)
SQL> alter system flush buffer_cache;
System altered.
Elapsed: 00:00:03.35
SQL> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.04
SQL>
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 732
undo change vector size 136
Elapsed: 00:00:00.05
SQL> create table chf.t_xifenfei_move_cast_N nologging tablespace users
2 as
3 select * from chf.t_xifenfei_move;
Table created.
Elapsed: 00:00:56.41
SQL> select a.name, b.value
2 from v$statname a, v$mystat b
3 where a.statistic# = b.statistic#
4 and lower(a.name) in
5 ('redo size','undo change vector size');
NAME VALUE
---------------------------------------------------------------- ----------
redo size 769848
undo change vector size 124944
SQL> select 769848-732 "redo size" from dual;
redo size
----------
769116
SQL> select 124944-136 "undo size" from dual;
undo size
----------
124808
这个试验产生的redo:769116,undo:124808
9.通过试验得出结论
1)sql hint中的nologgging无效
2)普通的cast(不含hint)，其本质是append，无nologgging
3)nologgging(表级别)可以使得cast效率较高
4)nologgging(表级别)+append(hint)可以使得insert效率较高
