- 浏览: 959790 次
- 性别:
- 来自: 杭州
文章分类
最新评论
-
孤星119:
好熟悉的数据库字段啊, 上家公司做的项目每天都跟这些字段打招呼 ...
Oracle exp compress参数引起的空间浪费 -
itspace:
quxiaoyong 写道遇到个问题,网上一搜,全他妈这篇文章 ...
数据库连接错误ORA-28547 -
quxiaoyong:
遇到个问题,网上一搜,全他妈这篇文章。你转来转去的有意思吗?
数据库连接错误ORA-28547 -
hctech:
关于version count过高的问题,不知博主是否看过ey ...
某客户数据库性能诊断报告 -
itspace:
invalid 写道写的不错,我根据这个来安装,有点理解错误了 ...
AIX 配置vncserver
顾名思义,dba_free_space指的是Oracle还有多少表空间剩余空间,其视图结构也相当简单:
SQL> desc dba_free_space
Name Null? Type
----------------------------------------- -------- ----------------------------
TABLESPACE_NAME VARCHAR2(30)
FILE_ID NUMBER
BLOCK_ID NUMBER
BYTES NUMBER
BLOCKS NUMBER
RELATIVE_FNO NUMBER
但是我们查询dba_free_space时,即表空间剩余空间常常是离碎的,比如
SQL> select * from dba_free_space where file_id=7;
TABLESPACE_NAME FILE_ID BLOCK_ID BYTES BLOCKS RELATIVE_FNO
------------------------------ ---------- ---------- ---------- ---------- ------------
ZHOUL 7 27145 983040 120 7
ZHOUL 7 27905 65536 8 7
ZHOUL 7 28937 7274496 888 7
ZHOUL 7 36617 851968 104 7
ZHOUL 7 60129 327680 40 7
ZHOUL 7 63497 720896 88 7
6 rows selected.
这是为什么呢?继续查看视图dba_free_space的创建语句:
create or replace view dba_free_space
(tablespace_name, file_id, block_id, bytes, blocks, relative_fno)
as
select ts.name, fi.file#, f.block#,
f.length * ts.blocksize, f.length, f.file#
from sys.ts$ ts, sys.fet$ f, sys.file$ fi
where ts.ts# = f.ts#
and f.ts# = fi.ts#
and f.file# = fi.relfile#
and ts.bitmapped = 0
union all
select /*+ ordered use_nl(f) use_nl(fi) */
ts.name, fi.file#, f.ktfbfebno,
f.ktfbfeblks * ts.blocksize, f.ktfbfeblks, f.ktfbfefno
from sys.ts$ ts, sys.x$ktfbfe f, sys.file$ fi
where ts.ts# = f.ktfbfetsn
and f.ktfbfetsn = fi.ts#
and f.ktfbfefno = fi.relfile#
and ts.bitmapped <> 0 and ts.online$ in (1,4) and ts.contents$ = 0
union all
select /*+ ordered use_nl(u) use_nl(fi) */
ts.name, fi.file#, u.ktfbuebno,
u.ktfbueblks * ts.blocksize, u.ktfbueblks, u.ktfbuefno
from sys.recyclebin$ rb, sys.ts$ ts, sys.x$ktfbue u, sys.file$ fi
where ts.ts# = rb.ts#
and rb.ts# = fi.ts#
and rb.file# = fi.relfile#
and u.ktfbuesegtsn = rb.ts#
and u.ktfbuesegfno = rb.file#
and u.ktfbuesegbno = rb.block#
and ts.bitmapped <> 0 and ts.online$ in (1,4) and ts.contents$ = 0
union all
select ts.name, fi.file#, u.block#,
u.length * ts.blocksize, u.length, u.file#
from sys.ts$ ts, sys.uet$ u, sys.file$ fi, sys.recyclebin$ rb
where ts.ts# = u.ts#
and u.ts# = fi.ts#
and u.segfile# = fi.relfile#
and u.ts# = rb.ts#
and u.segfile# = rb.file#
and u.segblock# = rb.block#
and ts.bitmapped = 0;
可以看到dba_free_space视图有三部分组成:fet$,x$ktfbfe,x$ktfbue,recyclebin$。其中fet$表格主要用于表空间extent管理是数据字典管理,x$ktfbue由前面的实验得知主要用于对位图块的扫描,recyclebin$主要用于管理回收站对象。
那x$ktfbfe主要用于做什么呢?
View: X$KTFBUE
[k]ernel [t]ablespace [f]ile [b]itmapped
[u]sed [e]xtents
Column Type Description
-------- ---- --------
ADDR RAW(4|8) address of this row/entry in the array or SGA
INDX NUMBER index number of this row in the fixed table array
INST_ID NUMBER oracle instance number
KTFBUESEGTSN NUMBER tablespace number of segment
KTFBUESEGFNO NUMBER segment relative file number
KTFBUESEGBNO NUMBER segment block number
KTFBUEEXTNO NUMBER extent number
KTFBUEFNO NUMBER extent file number
KTFBUEBNO NUMBER extent block number
KTFBUEBLKS NUMBER extent length
打开10046事件跟踪x$ktfbfe
SQL> ALTER SESSION SET EVENTS '10046 trace name context forever, level 12';
Session altered.
SQL> select * from x$ktfbfe;
ADDR INDX INST_ID KTFBFETSN KTFBFEFNO KTFBFEBNO KTFBFEBLKS
-------- ---------- ---------- ---------- ---------- ---------- ----------
B7F57A70 0 1 0 1 69769 632
B7F57A70 1 1 1 2 233 18328
B7F57A70 2 1 2 3 36953 80
B7F57A70 3 1 2 3 37041 40
B7F57A70 4 1 2 3 37121 8
。。。
SQL> ALTER SESSION SET EVENTS '10046 trace name context off';
Session altered.
打开跟踪文件,首先Oracle对x$ktfbfe进行解析
PARSING IN CURSOR #1 len=22 dep=0 uid=0 oct=3 lid=0 tim=1273325024428885 hv=502180737 ad='2674fde8'
select * from x$ktfbfe
END OF STMT
PARSE #1:c=0,e=130,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,tim=1273325024428880
BINDS #1:
EXEC #1:c=0,e=78,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,tim=1273325024429032
WAIT #1: nam='SQL*Net message to client' ela= 1 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1273325024429077
其次Oracle进一步解析ts$表,获取满足条件的ts#和flags
PARSING IN CURSOR #2 len=100 dep=1 uid=0 oct=3 lid=0 tim=1273325024429259 hv=3768030067 ad='25b84394'
select ts#, flags from ts$ where bitmapped <> 0 and contents$ = 0 and (online$ = 1 or online$ = 4)
END OF STMT
PARSE #2:c=0,e=91,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024429255
BINDS #2:
EXEC #2:c=1000,e=50,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024429371
WAIT #2: nam='db file sequential read' ela= 39 file#=1 block#=57 blocks=1 obj#=16 tim=1273325024442859
WAIT #2: nam='db file scattered read' ela= 130 file#=1 block#=58 blocks=7 obj#=16 tim=1273325024443240
FETCH #2:c=1000,e=13908,p=8,cr=4,cu=0,mis=0,r=1,dep=1,og=4,tim=1273325024443299
最后Oracle解析file$,传入绑定变量0,1,2...8
PARSING IN CURSOR #3 len=36 dep=1 uid=0 oct=3 lid=0 tim=1273325024443480 hv=1570213724 ad='27af1440'
select file# from file$ where ts#=:1
END OF STMT
PARSE #3:c=0,e=80,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024443476
BINDS #3:
kkscoacd
Bind#0
oacdty=02 mxl=22(22) mxlc=00 mal=00 scl=00 pre=00
oacflg=08 fl2=0001 frm=00 csi=00 siz=24 off=0
kxsbbbfp=b7f65180 bln=22 avl=01 flg=05
value=0
EXEC #3:c=0,e=119,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024443693
WAIT #3: nam='db file sequential read' ela= 14835 file#=1 block#=113 blocks=1 obj#=16 tim=1273325024458576
WAIT #3: nam='db file sequential read' ela= 236 file#=1 block#=114 blocks=1 obj#=16 tim=1273325024458882
FETCH #3:c=999,e=15195,p=2,cr=3,cu=0,mis=0,r=1,dep=1,og=4,tim=1273325024458914
FETCH #3:c=0,e=8,p=0,cr=1,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024458949
STAT #3 id=1 cnt=1 pid=0 pos=1 obj=17 op='TABLE ACCESS FULL FILE$ (cr=4 pr=2 pw=0 time=15194 us)'
WAIT #1: nam='db file sequential read' ela= 16 file#=1 block#=2 blocks=1 obj#=-1 tim=1273325024459119
WAIT #1: nam='db file sequential read' ela= 15 file#=1 block#=3 blocks=1 obj#=-1 tim=1273325024459190
FETCH #1:c=2999,e=30138,p=12,cr=8,cu=2,mis=0,r=1,dep=0,og=1,tim=1273325024459250
WAIT #1: nam='SQL*Net message from client' ela= 244 driver id=1650815232 #bytes=1 p3=0 obj#=-1 tim=1273325024459537
FETCH #2:c=0,e=9,p=0,cr=1,cu=0,mis=0,r=1,dep=1,og=4,tim=1273325024459584
。。。
PARSING IN CURSOR #3 len=36 dep=1 uid=0 oct=3 lid=0 tim=1273325024482416 hv=1570213724 ad='27af1440'
select file# from file$ where ts#=:1
END OF STMT
PARSE #3:c=0,e=13,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024482412
BINDS #3:
kkscoacd
Bind#0
oacdty=02 mxl=22(22) mxlc=00 mal=00 scl=00 pre=00
oacflg=08 fl2=0001 frm=00 csi=00 siz=24 off=0
kxsbbbfp=b7f65134 bln=22 avl=02 flg=05
value=7
EXEC #3:c=0,e=92,p=0,cr=0,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024482587
FETCH #3:c=0,e=22,p=0,cr=3,cu=0,mis=0,r=1,dep=1,og=4,tim=1273325024482634
FETCH #3:c=0,e=5,p=0,cr=1,cu=0,mis=0,r=0,dep=1,og=4,tim=1273325024482666
STAT #3 id=1 cnt=1 pid=0 pos=1 obj=17 op='TABLE ACCESS FULL FILE$ (cr=4 pr=0 pw=0 time=19 us)'
WAIT #1: nam='db file sequential read' ela= 17 file#=6 block#=2 blocks=1 obj#=-1 tim=1273325024482802
WAIT #1: nam='db file sequential read' ela= 15 file#=6 block#=3 blocks=1 obj#=-1 tim=1273325024482875
FETCH #2:c=0,e=7,p=0,cr=1,cu=0,mis=0,r=1,dep=1,og=4,tim=1273325024482917
通过查看跟踪文件,我们可以看到Oracle对x$ktfbfe表格的查询,最终会转换成对ts$的查询,通过条件过滤定位file$,然后从文件的2号block和3号block去取得数据。
我们知道每个数据文件的2号至-8号block是关于extent map的block。
从block type为1d可以知道这个block类型为KTFB Bitmapped File Space Header
BBED> dump block 2 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 2 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1da20000 0200c001 1fb3840e 000a0304 15fd0000 07000000 08000000 60f80000
<32 bytes per line>
从block type为12可以知道这个block类型为KTFB Bitmapped File Space Bitmap
BBED> dump block 3 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 3 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1ea20000 0300c001 1fb3840e 000a0104 35cd0000 07000000 09000000 00000000
<32 bytes per line>
从以上分析中我们推断出,Oracle查看x$ktfbfe,其实就是对Oracle 数据文件的block 2至block 8扫描(本例block 3-8为空,则跳过不扫描)。
从dba_free_space视图创建脚本中,我们还看到了表格recyclebin$内容的选取
继续测试:
在数据库中删除一张表格RBOTEST,其数据量有52567
SQL> select count(*) from RBOTEST;
COUNT(*)
----------
52567
SQL> drop table RBOTEST;
Table dropped.
刷内存,保证脏块刷出至数据文件
SQL> alter system flush buffer_cache;
System altered.
在recyclebin中我们看到了删除表格
SQL> show recyclebin
ORIGINAL NAME RECYCLEBIN NAME OBJECT TYPE DROP TIME
---------------- ------------------------------ ------------ -------------------
RBOTEST BIN$oeDriA+aATTgQBCsowQS+Q==$0 TABLE 2011-04-27:14:55:03
在基表中也存在
SQL> select OBJ#,OWNER#,ORIGINAL_NAME,FILE#,BLOCK# ,FLAGS,SPACE from recyclebin$;
OBJ# OWNER# ORIGINAL_NAME FILE# BLOCK# FLAGS SPACE
---------- ---------- -------------------------------- ---------- ---------- ---------- ----------
246366 60 RBOTEST_OBJ 7 29579 18 128
246367 60 RBOTEST_OWNER# 7 29707 18 112
246365 60 RBOTEST 7 27147 30 768
但是在x$ktfbfe显示依然是删除前的状态
SQL> select * from x$ktfbfe
2 where ktfbfefno=7;
ADDR INDX INST_ID KTFBFETSN KTFBFEFNO KTFBFEBNO KTFBFEBLKS
-------- ---------- ---------- ---------- ---------- ---------- ----------
B7F57A70 50 1 8 7 29817 8
B7F57A70 51 1 8 7 36617 104
B7F57A70 52 1 8 7 60129 40
B7F57A70 53 1 8 7 63497 88
通过bbed查看block状态,发现checkval值未变,这说明Oracle在Oracle 10g中drop 表格时extent map并未发生变化
BBED> dump block 2 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 2 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1da20000 0200c001 1fb3840e 000a0304 15fd0000 07000000 08000000 60f80000
<32 bytes per line>
BBED> dump block 3 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 3 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1ea20000 0300c001 1fb3840e 000a0104 35cd0000 07000000 09000000 00000000
<32 bytes per line>
清空回收站
SQL> purge recyclebin;
Recyclebin purged.
SQL> select OBJ#,OWNER#,ORIGINAL_NAME,FILE#,BLOCK# ,FLAGS,SPACE from recyclebin$;
no rows selected
继续查看x$ktfbfe和物理上block状态,发现未变,继续刷内存。
SQL> alter system flush buffer_cache;
System altered.
SQL> select * from x$ktfbfe
2 where ktfbfefno=7;
ADDR INDX INST_ID KTFBFETSN KTFBFEFNO KTFBFEBNO KTFBFEBLKS
-------- ---------- ---------- ---------- ---------- ---------- ----------
B7F26A58 47 1 8 7 27145 120
B7F26A58 48 1 8 7 27905 8
B7F26A58 49 1 8 7 28937 888
B7F26A58 50 1 8 7 36617 104
B7F26A58 51 1 8 7 60129 40
B7F26A58 52 1 8 7 63497 88
6 rows selected.
BBED> dump block 2 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 2 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1da20000 0200c001 5879930e 000a0104 955b0000 07000000 08000000 60f80000
<32 bytes per line>
BBED> dump block 3 offset 0 count 32
File: /oradata/mcstar/zhoul01.dbf (0)
Block: 3 Offsets: 0 to 31 Dba:0x00000000
------------------------------------------------------------------------
1ea20000 0300c001 5879930e 000a0104 6e0e0000 07000000 09000000 00000000
<32 bytes per line>
可以看到x$ktfbfe和block均发生了变化。
通过对dba_free_space的研究我们可以得出以下结论:
1、对x$ktfbfe的扫描,其实是物理上对数据文件2-8号block的扫描
2、在Oracle 10g,在不带参数purge,drop表格时,并不会对数据文件头extent map更新,通过这种方式减少了Oracle对extent map争用的可能性,这也是dba_free_space视图创建脚本中需要对基表recyclebin$选择的原因之一。曾经碰到过一案例,回收站对象太多导致执行dba_free_space时间很长。
3、在对回收站清空后,会更新数据文件头extent map,但命令purge recyclebin并不会引起对象基表的checkpoint。
发表评论
-
buffer cache 的内部结构
2020-03-18 14:21 517BUFFER CACHE作为数据块的 ... -
Oracle OMC介绍
2020-03-18 13:19 439Oracle管理云服务(OMC)的大数据平台,自动收集的企业 ... -
参加Oracle勒索病毒防范专题培训会议
2019-09-27 17:15 4222019年7月22日,受邀参加Oracle勒索病毒防范专题培训 ... -
记一次内存换IO的Oracle优化
2019-09-27 16:50 785某客户数据库从P595物理 ... -
如何定位Oracle SQL执行计划变化的原因
2019-07-03 14:49 1353性能优化最难的是能够 ... -
如何定位Oracle SQL执行计划变化的原因
2018-10-30 09:24 1185性能优化最难的是能够 ... -
数据库性能优化目标
2018-10-08 10:59 467从数据库性能优化的场 ... -
数据库无法打开的原因及解决办法
2018-10-05 20:45 1913数据库的启动是一个相当复杂的过程。比如,Oracle在启动之前 ... -
怎么样彻底删除数据库?
2018-09-18 11:10 551Oracle提供了drop database命令用来删除数据库 ... -
Oracle减少日志量的方法
2018-09-10 10:17 808LGWR进程将LOG BUFFER中的 ... -
如何快速关闭数据库
2018-09-09 13:14 1195“一朝被蛇咬,十年怕井绳”。在没被“蛇”咬之前,很多DBA喜欢 ... -
关于《如何落地智能化运维》PPT
2018-05-17 10:19 1087在DTCC 2018发表《如何落地智能化运维》演讲,主要内容如 ... -
记录在redhat5.8平台安装oracle11.2容易忽视的几个问题
2018-05-11 19:58 530问题一:ping不通问题 在虚拟机上安装好linux系统后, ... -
《Oracle DBA实战攻略》第一章
2018-05-11 10:42 890即日起,不定期更新《OracleDBA实战攻略》一书电子版,请 ... -
Oracle 12c新特性
2018-05-11 10:33 852查询所有pdb [oracle@gj4 ~]$ sqlplu ... -
关于修改memory_target的值后数据库无法启动的问题
2017-02-28 12:24 3922操作系统:RHEL6.5 数据库版本:11.2.0.4 ... -
10g rac安装error while loading shared libraries libpthread.so.0 问题
2017-02-28 12:22 63311g rac安装在二节点跑脚本一般会报此错误: 解决这个问 ... -
记一次Oracle会话共享模式故障处理过程
2017-02-27 19:16 753故障简述 XXX第八人民医院HIS数据库7月13日11点左右从 ... -
RESMGR:cpu quantum等待事件处理过程
2017-02-27 18:23 2474由于数据库上线过程中出现大量的RESMGR:cpu quant ... -
谈谈log file sync
2014-03-19 14:18 1679数据库中的log file sync等待事件指的是,当user ...
相关推荐
dba_extents:数据库中所有分区的信息 dba_free_space:所有表空间中的自由分区 dba_indexs:关于数据库中所有索引的描述 dba_ind_columns:在所有表及聚集上压缩索引的列 dba_objects:数据库中所有的对象 dba_...
from dba_free_space group by tablespace_name; SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE, (B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE" FROM SYS.SM$TS_AVAIL A,...
FROM SYS.DBA_FREE_SPACE GROUP BY TABLESPACE_NAME) F, (SELECT DD.TABLESPACE_NAME, ROUND(SUM(DD.BYTES) / (1024 * 1024), 2) TOT_GROOTTE_MB FROM SYS.DBA_DATA_FILES DD GROUP BY DD.TABLESPACE_...
<br>create or replace view ts_blocks_v as select tablespace_name,block_id,bytes,blocks,'free space' segment_name from dba_free_space union all select tablespace_name,block_id,bytes,...
from dba_free_space group by tablespace_name, file_id) a, dba_data_files b, (select owner, segment_name, file_id, sum(bytes) bytes from dba_extents where owner = 'owner name' group by ...
GRANT SELECT ON "SYS"."DBA_FREE_SPACE" TO "MAPGISDBA" WITH GRANT OPTION; GRANT SELECT ON "SYS"."DBA_TABLESPACES" TO "MAPGISDBA" WITH GRANT OPTION; GRANT SELECT ON "SYS"."DBA_ROLE_PRIVS" TO ...
sum(nvl(a.bytes,0)) 剩余空间,sum(nvl(a.bytes,0))/(b.bytes)*100 剩余百分比 from dba_free_space a,dba_data_files b where a.file_id=b.file_id group by b.tablespace_name,b.file_id,b.bytes order by b....
sqlplus ecifpub/ecifpub@ECIFDB ... from sys.dba_free_space group by TABLESPACE_NAME) b where a.TABLESPACE_NAME = b.TABLESPACE_NAME (+) order by ((a.BYTES-b.BYTES)/a.BYTES) desc; quit !
通过sql语句查看oracle的表空间使用情况,主要是访问dba_data_files和dba_free_space两张表
from dba_free_space group by tablespace_name) order by \"free_space(M)\"; 7、查看数据库库对象 select owner, object_type, status, count(*) count# from all_objects group by owner,object_type,...
..........\Free_Space_TableSpace.sql ..........\Health.sql ..........\High_Water_Mark.sql ..........\Index_Extents.sql ..........\Index_Partitions.sql ..........\Jobs.sql ..........\Jobs_...
一。查询篇 1.查询oracle表空间的使用情况 select b.file_id 文件ID, b.tablespace_name 表空间, b.file_name 物理...0))/(b.bytes)*100 剩余百分比 from dba_free_space a,dba_data_files b where a.file_id=b.fil
代码如下:select tablespace_name,file_id,block_id,bytes,blocks from dba_free_space; 2、增加Oracle表空间 先查询数据文件名称、大小和路径的信息,语句如下: 代码如下:select tablespace_name,file_id,bytes,...
大多数的有经验的 Oracle DBA 都会 首先用这个命令来快速查看一下服务器负载情况,因为 w 命令在几乎所有的 Unix 下 都可以用。 # w 10:02AM up 60 days, 18:46, 3 users, load average: 0.32, 0.39, 0.43 User ...
2.3.2 使用 DBMS_SPACE.FREE _BLOCK 2.4 管理锁争用 2.4.1 怎样查找产生锁的 SQL 语句 2.4.2 怎样释放锁 2.4.3 怎样删除用户会话 2.4.4 怎样从数据字典中提取视图创建 命令 2.4.5 怎样从数据字典中提取索引...
from dba_free_space group by tablespace_name; SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE, (B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE" FROM SYS.SM$TS_...
from dba_free_space group by tablespace_name) a, (select round(sum(bytes)/1024/1024) mbytes_alloc,tablespace_name from dba_data_files group by tablespace_name) b where a.tab
from dba_free_space group by tablespace_name; SELECT A.TABLESPACE_NAME,A.BYTES TOTAL,B.BYTES USED, C.BYTES FREE, (B.BYTES*100)/A.BYTES "% USED",(C.BYTES*100)/A.BYTES "% FREE" FROM SYS.SM$TS_...
2.2 ORACLE实例..................................................................................................................................10 2.2.1 ORACLE进程........................................