自定义统计结果脚本mystat

mystat.sql和相应的mystat2.sql用于展示完成某操作之前和之后的某些Oracle“统计结果”的变化情况。mystat.sql只是获得统计结果的开始值：
mystat.sql脚本内容如下:

set echo off
set verify off
column value new_val V
define S="&1"
set autotrace off
select a.name, b.value
from v$statname a, v$mystat b
where a.statistic# = b.statistic#
and lower(a.name) like '%' || lower('&S')||'%'
/
set echo on

mystat2.sql用于报告统计结果的变化情况（差值）：

set echo off
set verify off
select a.name, b.value V, to_char(b.value-&V,'999,999,999,999') diff
from v$statname a, v$mystat b
where a.statistic# = b.statistic#
and lower(a.name) like '%' || lower('&S')||'%'
/
set echo on

例如，要查看某个UPDATE生成的redo数，可以使用以下命令：

sys@DEVELOP> @/oracle/product/11.2/sqlplus/mystat.sql "redo size"

NAME                                                                  VALUE
---------------------------------------------------------------- ----------
redo size                                                         756293676
redo size for lost write detection                                        0
redo size for direct writes                                               0

sys@DEVELOP> update t1 set aac009='1';

795680 rows updated.

sys@DEVELOP> @/oracle/product/11.2/sqlplus/mystat2.sql

NAME                                                                      V DIFF
---------------------------------------------------------------- ---------- ----------------
redo size                                                        1139306496    1,139,306,496
redo size for lost write detection                                        0                0
redo size for direct writes                                               0                0

由此可见，795,680行记录的UPDATE会生成1,139,306,496字节的redo.