nologging与append测试
早前解决提升批量插入性能时的做的测试，翻出来，贴一下。
在对数据进行批量insert时，正确使用nologging和append，不仅能够极大的操作提高效率同时也能免去不必要的redo日志。通过以下4个实验看他们的正确使用。
环境：
OS：WindowsXP
DB：Oracle9.2.0.1
1，实验一：归档模式下，创建表不使用nologging
代码
SQL> archive log list
Database log mode Archive Mode
Automatic archival Enabled
Archive destination E:\oracle\ora92\RDBMS
Oldest online log sequence 12
Next log sequence to archive 14
Current log sequence 14
SQL> create table ttt as select object_id,object_name from dba_objects where 1=0;
Table created.
SQL> column sid format 9999
SQL> column name format a50
SQL> column value format 999999999
SQL> select b.sid,a.name,a.value from v$sysstat a,v$mystat b
2 where a.statistic#=b.statistic# and a.name like 'redo size%';
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 1469088
SQL> /
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 1469088
SQL> insert into ttt select object_id,object_name from dba_objects;
30899 rows created.
SQL> commit;
Commit complete.
SQL> column sid format 9999
SQL> column name format a50
SQL> column value format 999999999
SQL> select b.sid,a.name,a.value from v$sysstat a,v$mystat b
2 where a.statistic#=b.statistic# and a.name like 'redo size%';
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 2775240
SQL> /
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 2775240
SQL> insert /*+APPEND*/into ttt select object_id,object_name from dba_objects;
30899 rows created.
SQL> commit;
Commit complete.
SQL> column sid format 9999
SQL> column name format a50
SQL> column value format 999999999
SQL> select b.sid,a.name,a.value from v$sysstat a,v$mystat b
2 where a.statistic#=b.statistic# and a.name like 'redo size%';
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 4019400
SQL> /
SID NAME VALUE
----- -------------------------------------------------- ----------
9 redo size 4019400
SQL> select (2775240-1469088) noappend,(4019400-2775240) append from dual;
NOAPPEND APPEND
---------- ----------
1306152 1244160
总结：在归档模式下，创建表时不使用nologging参数，对日后的表操作没有实质性影响，加与不加apped参数生成的redo日志基本相同，效率得不到提升。
2，实验二：归档模式下，创建表使用nologging
代码
SQL
>
archive
log
list
Database
log
mode Archive Mode
Automatic archival Enabled
Archive destination E:\oracle\ora92\RDBMS
Oldest online
log
sequence
12
Next
log
sequence
to
archive
14
Current
log
sequence
14
SQL
>
create
table
tttt nologging
as
select
object_id
,
object_name
from
dba_objects;
Table
created.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
7066492
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
7066492
SQL
>
insert into tttt select object_id,object_name from
dba_objects;
30900
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
8345292
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
8345292
SQL
>
insert /*+APPEND*/into tttt select object_id,object_name from
dba_objects;
30900
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
8399484
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
8399484
SQL
>
select
(
8399484
-
8345292
) append,(
8345292
-
7066492
) noappend
from
dual;
APPEND NOAPPEND
--
-------- ----------
54192
1278800
3，实验三：非归档模式下，创建表不使用nologging
代码
SQL
>
archive
log
list
Database
log
mode No Archive Mode
Automatic archival Disabled
Archive destination E:\oracle\ora92\RDBMS
Oldest online
log
sequence
12
Current
log
sequence
14
SQL
>
create
table
tt
as
select
object_id
,
object_name
from
dba_objects
where
1
=
0
;
Table
created.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
3416124
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
3442132
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
3442132
SQL
>
insert /*+APPEND*/into
tt
2
select object_id,object_name from
dba_objects;
30898
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
3467448
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
3519424
SQL
>
insert into tt select object_id,object_name from
dba_objects;
30898
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
4798068
SQL
>
select
(
3467448
-
3442132
) append,(
4798068
-
3519424
) noappend
from
dual;
APPEND NOAPPEND
--
-------- ----------
25316
1278644
4，实验四：非归档模式下，创建表使用nologging
代码
SQL
>
archive
log
list
Database
log
mode No Archive Mode
Automatic archival Disabled
Archive destination E:\oracle\ora92\RDBMS
Oldest online
log
sequence
12
Current
log
sequence
14
SQL
>
create
table
tt nologging
as
select
object_id
,
object_name
from
dba_objects
where
1
=
0
;
Table
created.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
246108
SQL
>
insert into tt select object_id,object_name from
dba_objects;
30900
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
1552440
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
1552440
SQL
>
insert /*+APPEND*/into tt select object_id,object_name from
dba_objects;
30900
rows created.
SQL
>
commit
;
Commit
complete.
SQL
>
column
sid format
9999
SQL
>
column
name format a50
SQL
>
column
value format
999999999
SQL
>
select
b.sid,a.name,a.value
from
v$sysstat a,v$mystat b
2
where
a.statistic#
=
b.statistic#
and
a.name
like
'
redo size%
'
;
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
1580736
SQL
>
/
SID NAME VALUE
--
--- -------------------------------------------------- ----------
9
redo size
1580736
SQL
>
select
(
1580736
-
1552440
) append,(
1552440
-
246108
) noappend
from
dual;
APPEND NOAPPEND
--
-------- ----------
28296
1306332
小结：
非归档模式下,不管创建表时nologging参数是否存在,只有使用append参数才能提高效率,减少redo生成量；
归档模式下,nologging和append参数同时使用，才能够提升效率，减少redo生成量。