这样的文件能够用sqlldr导入么?

我测试了一下，试验证明是可以的，sqlldr支持多字符分隔符文件导入。
首先看我的数据文件和控制文件:

[oracle@jumper tmp]$ cat data.ctl
load data
into table TEST
fields terminated by "|+|"
(
T_ID,
T_VOL
)
[oracle@jumper tmp]$ cat data.txt
20021228000000|+|00120000
20021228000000|+|00130000
20021228000000|+|00140000
20021||8000000|+|00140000
20021++8000000|+|00140000

[oracle@jumper tmp]$ sqlplus eygle/eygle

SQL*Plus: Release 9.2.0.4.0 - Production on Tue Nov 21 13:21:16 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> create table test
2 (T_ID varchar2(20),
3 T_VOL varchar2(20)
4 );

Table created.

SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

加载数据:

[oracle@jumper tmp]$ sqlldr eygle/eygle control=data.ctl data=data.txt

SQL*Loader: Release 9.2.0.4.0 - Production on Tue Nov 21 13:23:53 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Commit point reached - logical record count 5
[oracle@jumper tmp]$ sqlplus eygle/eygle

SQL*Plus: Release 9.2.0.4.0 - Production on Tue Nov 21 13:23:57 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> select * from test;

T_ID T_VOL
-------------------- --------------------
20021228000000 00120000
20021228000000 00130000
20021228000000 00140000
20021||8000000 00140000
20021++8000000 00140000

SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

只作了简单验证，不知道复杂情况会不会有问题。

-The End-

发现以下两个命令很有用:

LSNRCTL> set current_listener <listener name>
LSNRCTL> set log_file <sid name>.log

使用set current_listener可以访问非缺省监听器，使用set log_file更改名称后，原来有问题的日志文件可以清除或实现日志重定位:

[oracle@jumper admin]$ lsnrctl

LSNRCTL for Linux: Version 9.2.0.4.0 - Production on 10-NOV-2006 16:54:16

Copyright (c) 1991, 2002, Oracle Corporation.  All rights reserved.

Welcome to LSNRCTL, type "help" for information.

LSNRCTL> set current_listener LISTENER1
Current Listener is LISTENER1
LSNRCTL> set log_file
Parameter Value: a.log
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
LISTENER1 parameter "log_file" set to a.log
The command completed successfully
LSNRCTL> status
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER1
Version                   TNSLSNR for Linux: Version 9.2.0.4.0 - Production
Start Date                10-NOV-2006 16:54:12
Uptime                    0 days 0 hr. 2 min. 6 sec
Trace Level               off
Security                  OFF
SNMP                      OFF
Listener Parameter File   /opt/oracle/product/9.2.0/network/admin/listener.ora
Listener Log File         /opt/oracle/product/9.2.0/network/log/a.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=172.16.33.11)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "conner" has 1 instance(s).
  Instance "conner", status UNKNOWN, has 1 handler(s) for this service...
Service "eygle" has 1 instance(s).
  Instance "eygle", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
LSNRCTL>

如果需要将这个修改永久化，需要使用save_config命令保存一下：

LSNRCTL> save_config
Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC)))
Saved LISTENER1 configuration parameters.
Listener Parameter File /opt/oracle/product/9.2.0/network/admin/listener.ora
Old Parameter File /opt/oracle/product/9.2.0/network/admin/listener.bak
The command completed successfully

此时listener.ora文件会被增加如下记录：

[oracle@jumper oracle]$ tail -5 /opt/oracle/product/9.2.0/network/admin/listener.ora

#----ADDED BY TNSLSNR 14-NOV-2006 16:39:12---
LOG_FILE_LISTENER1 = a.log
#--------------------------------------------

记录一下。

-The End-

我简单做了一个例子，实现以上要求.
首先进行适当授权：

[oracle@jumper oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.4.0 - Production on Tue Nov 7 21:07:56 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> grant create public database link to eygle;

Grant succeeded.
SQL> grant all on dbms_flashback to eygle;

Grant succeeded.

建立DB Link:

SQL> connect eygle/eygle
Connected.
SQL> create public database link hsbill using 'hsbill';

Database link created.

SQL> select db_link from dba_db_links;

DB_LINK
---------------------------------------------------
HSBILL

SQL> select * from dual@hsbill;

D
-
X

此后可以尝试使用DB Link进行远程和本地执行:

SQL> set serveroutput on
SQL> set feedback off
SQL> declare
2 r_gname varchar2(40);
3 l_gname varchar2(40);
4 begin
5 execute immediate
6 'select GLOBAL_NAME from global_name@hsbill' into r_gname;
7 dbms_output.put_line('gname of remote:'||r_gname);
8 select GLOBAL_NAME into l_gname from global_name;
9 dbms_output.put_line('gname of locald:'||l_gname);
10 end;
11 /
gname of remote:HSBILL.HURRAY.COM.CN
gname of locald:EYGLE

远程Package或Function调用也可以随之实现:

SQL> declare
2 r_scn number;
3 l_scn number;
4 begin
5 execute immediate
6 'select dbms_flashback.GET_SYSTEM_CHANGE_NUMBER@hsbill from dual' into r_scn;
7 dbms_output.put_line('scn of remote:'||r_scn);
8 end;
9 /
scn of remote:18992092687

SQL>

-The End-

登陆检查主库，警告日志记录了错误信息:

*** 2006-10-30 07:32:10.614
kcrrfail: dest:2 err:12560 force:0
ORA-12560: TNS:protocol adapter error
*** 2006-10-30 07:34:10.615
Error 12541 connecting to destination LOG_ARCHIVE_DEST_2 standby host 'bmarksb'
Error 12541 attaching to destination LOG_ARCHIVE_DEST_2 standby host 'bmarksb'
Heartbeat failed to connect to standby 'bmarksb'. Error is 12541.
*** 2006-10-30 07:34:10.615
kcrrfail: dest:2 err:12541 force:0
ORA-12541: TNS:no listener
*** 2006-10-30 07:36:10.615
Error 12541 connecting to destination LOG_ARCHIVE_DEST_2 standby host 'bmarksb'
Error 12541 attaching to destination LOG_ARCHIVE_DEST_2 standby host 'bmarksb'
Heartbeat failed to connect to standby 'bmarksb'. Error is 12541.

马上登陆从库主机，手工启动备用数据库：

[oracle@wapcom2 bdump]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.6.0 - Production on Mon Oct 30 08:17:24 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to an idle instance.

SQL> startup nomount;
ORACLE instance started.

Total System Global Area 470881780 bytes
Fixed Size 452084 bytes
Variable Size 167772160 bytes
Database Buffers 301989888 bytes
Redo Buffers 667648 bytes
SQL> alter database mount standby database;

Database altered.

SQL> alter database recover managed standby database disconnect from session;

Database altered.

SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.6.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.6.0 - Production
[oracle@wapcom2 bdump]$ lsnrctl start

观察从库的日志信息，发现归档可以自动应用:

[oracle@wapcom2 bdump]$ tail -f alert_bmark.log
Standby Database mounted.
Completed: alter database mount standby database
Mon Oct 30 08:19:23 2006
alter database recover managed standby database disconnect from session
Attempt to start background Managed Standby Recovery process
MRP0 started with pid=12
MRP0: Background Managed Standby Recovery process started
Media Recovery Waiting for thread 1 seq# 5151
Mon Oct 30 08:19:29 2006
Completed: alter database recover managed standby database di
Mon Oct 30 08:22:58 2006
Media Recovery Log /opt/oracle/oradata/bmark/stdarch/1_5151.arc
Media Recovery Log /opt/oracle/oradata/bmark/stdarch/1_5152.arc
Media Recovery Log /opt/oracle/oradata/bmark/stdarch/1_5153.arc
Media Recovery Log /opt/oracle/oradata/bmark/stdarch/1_5154.arc
Media Recovery Log /opt/oracle/oradata/bmark/stdarch/1_5155.arc
Media Recovery Waiting for thread 1 seq# 5156

再检查原因，发现原来是主机出现问题，在夜间不断重起：

-bash-2.05b$ last |grep reboot
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 08:10 (02:14)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 07:51 (02:32)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 07:38 (02:45)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 07:35 (02:48)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 07:21 (03:02)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 07:18 (03:05)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 06:39 (03:44)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 06:37 (03:46)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 06:32 (03:51)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 06:03 (04:21)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 01:48 (08:36)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 01:23 (09:01)
reboot system boot 2.4.21-15.ELsmp Mon Oct 30 00:39 (09:44)

初步看来是硬件出现了故障，最近的硬件故障极为频繁，年底也到了事故多发期。
提醒大家也多多注意。

参考文档：
http://www.eygle.com/ha/dataguard-step-by-step.htm

-The End-

我们知道，通过SYS_CONTEXT函数可以获得这部分信息，当前用户的ip等信息可以通过如下命令轻易获取：

SQL> select sys_context('userenv','host') from dual;

SYS_CONTEXT('USERENV','HOST')
--------------------------------------------------------------------------------
WORKGROUP\GQGAI

SQL> select sys_context('userenv','ip_address') from dual;

SYS_CONTEXT('USERENV','IP_ADDR
--------------------------------------------------------------------------------
172.16.34.20

可是如果我们希望获取其它session的地址信息等，通过SYS_CONTEXT函数就只能通过LOGON触发器来完成。

而如果没有触发器记录，则我们可以通过UTL_INADDR Package来实现。
我们看一下UTL_INADDR包获取ip等信息的实现原理。

我们在数据库中进行如下查询：

[oracle@jumper oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.4.0 - Production on Wed Oct 25 11:24:22 2006

Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> !
[oracle@jumper oracle]$ ps -ef|grep sql
oracle 14700 14663 1 11:24 pts/0 00:00:00 sqlplus
oracle 14732 14702 0 11:24 pts/0 00:00:00 grep sql
[oracle@jumper oracle]$ ps -ef|grep LO
oracle 14701 14700 0 11:24 ? 00:00:00 oracleeygle (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
oracle 14734 14702 0 11:24 pts/0 00:00:00 grep LO
[oracle@jumper oracle]$ exit
exit

SQL> SELECT UTL_INADDR.get_host_address('www.anysql.net') from dual;

UTL_INADDR.GET_HOST_ADDRESS('WWW.ANYSQL.NET')
---------------------------------------------------------------------
208.113.151.109

在Linux中我们通过strace跟踪这个进程，可以得到以下堆栈信息:

[oracle@jumper oracle]$ strace -p 14701
Process 14701 attached - interrupt to quit
read(7, "\0\313\0\0\6\0\0\0\0\0\3^\10a\200\0\0\0\0\0\0@\342\22\10"..., 2064) = 203
gettimeofday({1161746697, 269895}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 30000}, ru_stime={0, 10000}, ...}) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
gettimeofday({1161746697, 270542}, NULL) = 0
gettimeofday({1161746697, 270670}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
gettimeofday({1161746697, 271614}, NULL) = 0
gettimeofday({1161746697, 271748}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
gettimeofday({1161746697, 272347}, NULL) = 0
gettimeofday({1161746697, 272699}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
gettimeofday({1161746697, 272989}, NULL) = 0
gettimeofday({1161746697, 273140}, NULL) = 0
gettimeofday({1161746697, 273273}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 10000}, ...}) = 0
gettimeofday({1161746697, 273771}, NULL) = 0
gettimeofday({1161746697, 275526}, NULL) = 0
getpid() = 14701
open("/etc/resolv.conf", O_RDONLY) = 12
fstat64(12, {st_mode=S_IFREG|0644, st_size=46, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6fba000
read(12, "search hurray.com.cn\nnameserver "..., 4096) = 46
read(12, "", 4096) = 0
close(12) = 0
munmap(0xb6fba000, 4096) = 0
socket(PF_UNIX, SOCK_STREAM, 0) = 12
connect(12, {sa_family=AF_UNIX, path="/var/run/.nscd_socket"}, 110) = -1 ENOENT (No such file or directory)
close(12) = 0
open("/etc/host.conf", O_RDONLY) = 12
fstat64(12, {st_mode=S_IFREG|0644, st_size=17, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6fba000
read(12, "order hosts,bind\n", 4096) = 17
read(12, "", 4096) = 0
close(12) = 0
munmap(0xb6fba000, 4096) = 0
futex(0xb71a1a20, FUTEX_WAKE, 2147483647) = 0
open("/etc/hosts", O_RDONLY) = 12
fcntl64(12, F_GETFD) = 0
fcntl64(12, F_SETFD, FD_CLOEXEC) = 0
fstat64(12, {st_mode=S_IFREG|0644, st_size=175, ...}) = 0
mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb6fba000
read(12, "# Do not remove the following li"..., 4096) = 175
read(12, "", 4096) = 0
close(12) = 0
munmap(0xb6fba000, 4096) = 0
open("/opt/oracle/product/9.2.0/lib/libnss_dns.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/tls/libnss_dns.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/i686/libnss_dns.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/libnss_dns.so.2", O_RDONLY) = 12
read(12, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\240\16"..., 512) = 512
fstat64(12, {st_mode=S_IFREG|0755, st_size=18632, ...}) = 0
old_mmap(NULL, 17100, PROT_READ|PROT_EXEC, MAP_PRIVATE, 12, 0) = 0xb6fb6000
old_mmap(0xb6fba000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 12, 0x3000) = 0xb6fba000
close(12) = 0
open("/opt/oracle/product/9.2.0/lib/libresolv.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/tls/libresolv.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/i686/libresolv.so.2", O_RDONLY) = -1 ENOENT (No such file or directory)
open("/lib/libresolv.so.2", O_RDONLY) = 12
read(12, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0\320(\0"..., 512) = 512
fstat64(12, {st_mode=S_IFREG|0755, st_size=76508, ...}) = 0
old_mmap(NULL, 73604, PROT_READ|PROT_EXEC, MAP_PRIVATE, 12, 0) = 0xb6fa4000
old_mmap(0xb6fb3000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, 12, 0xf000) = 0xb6fb3000
old_mmap(0xb6fb4000, 8068, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xb6fb4000
close(12) = 0
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) = 12
connect(12, {sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("208.113.151.109")}, 28) = 0
send(12, "\324#\1\0\0\1\0\0\0\0\0\0\3www\5anysql\3com\0\0\1\0\1", 31, 0) = 31
gettimeofday({1161746697, 286025}, NULL) = 0
poll([{fd=12, events=POLLIN, revents=POLLIN}], 1, 5000) = 1
ioctl(12, FIONREAD, [74]) = 0
recvfrom(12, "\324#\201\200\0\1\0\1\0\1\0\0\3www\5anysql\3com\0\0\1\0"..., 1024, 0,
{sa_family=AF_INET, sin_port=htons(53), sin_addr=inet_addr("208.113.151.109")}, [16]) = 74
close(12) = 0
gettimeofday({1161746697, 290245}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 20000}, ...}) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 20000}, ...}) = 0
gettimeofday({1161746697, 291553}, NULL) = 0
write(10, "\2\275\0\0\6\0\0\0\0\0\20\31\266\344\217\3700\320\341S"..., 701) = 701
read(7, "\0\215\0\0\6\0\0\0\0\0\3^\t@\0\0\0\1\0\0\0\0\0\0\0\0\0"..., 2064) = 141
gettimeofday({1161746697, 294898}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 20000}, ...}) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 20000}, ...}) = 0
gettimeofday({1161746697, 295496}, NULL) = 0
getrusage(RUSAGE_SELF, {ru_utime={0, 40000}, ru_stime={0, 20000}, ...}) = 0
gettimeofday({1161746697, 295847}, NULL) = 0
gettimeofday({1161746697, 295981}, NULL) = 0
lseek(9, 1024, SEEK_SET) = 1024
read(9, "\30\0$\0007\0@\0J\0V\0`\0i\0t\0~\0\232\0\245\0\320\0\330"..., 512) = 512
lseek(9, 47104, SEEK_SET) = 47104
read(9, "\f\0^\5\0\0P\0x\5\0\0\214\0y\5\0\0\250\0z\5\0\0\313\0{"..., 512) = 512
gettimeofday({1161746697, 297024}, NULL) = 0
write(10, "\0\202\0\0\6\0\0\0\0\0\4\1\0\0\0\1\1\0\0\0{\5\0\0\0\0\1"..., 130) = 130
read(7,
Process 14701 detached

在这个信息中，我们注意到Oracle顺序访问了如下文件来完成地址定位：

open("/etc/resolv.conf", O_RDONLY) = 12
open("/etc/host.conf", O_RDONLY) = 12
open("/etc/hosts", O_RDONLY) = 12

首先获取域名解析服务器，在根据host.conf文件确定解析顺序，因为缺省hosts文件优先，又继续读取/etc/hosts文件。

如果hosts文件存在解析关系，则返回信息；如果不存在，则继续问询DNS服务器，获得解析地址，如果不能解析，则会出错：

SQL> select UTL_INADDR.get_host_address('www.a.com') from dual;
select UTL_INADDR.get_host_address('www.a.com') from dual
*
ERROR at line 1:
ORA-29257: host www.a.com unknown
ORA-06512: at "SYS.UTL_INADDR", line 35
ORA-06512: at "SYS.UTL_INADDR", line 40
ORA-06512: at line 1

这就是UTL_INADDR包的工作原理。

-The End-

其实这个问题，最好的方法是用opatch工具，可以查询得到详细的安装组件版本。
这个可以参考我的网站链接:
http://www.eygle.com/internal/Use.Opatch.apply.Interim.Patch.htm

这里想说说其他的几个视图。有朋友提到了v$version 和 product_component_version 两个视图。
我们来看一下这两者有意思的关系.

首先看看两者的输出:

SQL> select * from PRODUCT_COMPONENT_VERSION;

PRODUCT VERSION STATUS
------------------------------ -------------------- ----------
NLSRTL 9.2.0.4.0 Production
Oracle9i Enterprise Edition 9.2.0.4.0 Production
PL/SQL 9.2.0.4.0 Production
TNS for Linux: 9.2.0.4.0 Production

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
PL/SQL Release 9.2.0.4.0 - Production
CORE 9.2.0.3.0 Production
TNS for Linux: Version 9.2.0.4.0 - Production
NLSRTL Version 9.2.0.4.0 - Production

似乎不同，是么？
那我们再来看看这两者的来源，可以借用一下sqlplus的autotrace功能:

SQL> set autotrace trace explain
SQL> select * from v$version;

Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE
1 0 FIXED TABLE (FULL) OF 'X$VERSION'

SQL> select * from PRODUCT_COMPONENT_VERSION;

Execution Plan
----------------------------------------------------------
0 SELECT STATEMENT Optimizer=CHOOSE
1 0 VIEW OF 'PRODUCT_COMPONENT_VERSION'
2 1 SORT (UNIQUE)
3 2 UNION-ALL
4 3 FIXED TABLE (FULL) OF 'X$VERSION'
5 3 FIXED TABLE (FULL) OF 'X$VERSION'

我们可以发现，这两者都来自底层表x$version，也就是说这两个视图同源，只不过展现有所不同而已。

查询一下x$version的基本信息:

SQL> col indx for 9999
SQL> col inst_id for 99
SQL> select * from x$version;

ADDR INDX INST_ID BANNER
-------- ----- ------- ----------------------------------------------------------------
B701CDCC 0 1 Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
B701CDCC 1 1 PL/SQL Release 9.2.0.4.0 - Production
B701CDCC 2 1 CORE 9.2.0.3.0 Production
B701CDCC 3 1 TNS for Linux: Version 9.2.0.4.0 - Production
B701CDCC 4 1 NLSRTL Version 9.2.0.4.0 - Production

v$version显然是较为单纯的View，那么PRODUCT_COMPONENT_VERSION经过怎样的处理呢？
我们看一下这个视图的创建语句，学习一下Oracle的SQL技术：

CREATE OR REPLACE VIEW SYS.product_component_version (product, VERSION,
status)
AS
(SELECT SUBSTR (banner, 1, INSTR (banner, 'Version') - 1),
SUBSTR (banner,
INSTR (banner, 'Version') + 8,
INSTR (banner, ' - ') - (INSTR (banner, 'Version') + 8)
),
SUBSTR (banner, INSTR (banner, ' - ') + 3)
FROM v$version
WHERE INSTR (banner, 'Version') > 0
AND ( (INSTR (banner, 'Version') < INSTR (banner, 'Release'))
OR INSTR (banner, 'Release') = 0
))
UNION
(SELECT SUBSTR (banner, 1, INSTR (banner, 'Release') - 1),
SUBSTR (banner,
INSTR (banner, 'Release') + 8,
INSTR (banner, ' - ') - (INSTR (banner, 'Release') + 8)
),
SUBSTR (banner, INSTR (banner, ' - ') + 3)
FROM v$version
WHERE INSTR (banner, 'Release') > 0
AND INSTR (banner, 'Release') < INSTR (banner, ' - '))

很多东西只要深入一点点，就能发现问题的本质。
是不是很好玩呢?

-The End-

有的trace文件中已经包含了地址转换，例如: 

而有时候trace文件里只包含一个RDBA，比如上周我们遇到的一个案例：

这里的Rdba我们怎样才能转换为文件号和数据块号呢?

通过手工转换，可以参考如下文章：

http://www.eygle.com/archives/2004/08/how_to_convert_rdba.html

Oracle同时提供一个系统包 dbms_utility 可以用于对RDBA进行转换。

注意，对于上面的 rdba: 0x08811ba3，首先要做一个16进制到10进制的转换，转换方法参考:

http://www.eygle.com/archives/2004/06/oracle_howto_convert.html

下面我们使用dbms_utility 来进行转换：

这样就可以通过dba_extents获得相关对象信息。

当然这里oer 8102.2 的信息已经告诉我们，出问题的是一个索引： 

-The End-

这时候我们可以使用Oracle提供的另外一个Hints: Leading 提示.

这个Hints在Oracle9i中的含义为:

The LEADING hint causes Oracle to use the specified table as the first table in the join order.

If you specify two or more LEADING hints on different tables, then all of them are ignored. If you specify the ORDERED hint, then it overrides all LEADING hints.

通过Leading 和 use_hash 提示连用,我们可以巧妙的影响SQL中表和结果集的Join顺序.

我们通过如下示例看一下这个提示是如何影响SQL执行的:

SQL> SELECT /*+ leading(t_max) use_hash(t_max t_middle) */ COUNT (*)
  2    FROM t_small, t_max, t_middle
  3  WHERE t_small.object_id = t_middle.object_id
  4  AND t_middle.object_id = t_max.object_id
  5  /

Execution Plan
----------------------------------------------------------
   0      SELECT STATEMENT Optimizer=CHOOSE (Cost=262 Card=1 Bytes=12)
   1    0   SORT (AGGREGATE)
   2    1     HASH JOIN (Cost=262 Card=400 Bytes=4800)
   3    2       HASH JOIN (Cost=225 Card=113776 Bytes=910208)
   4    3         TABLE ACCESS (FULL) OF 'T_MAX' (Cost=151 Card=113792 Bytes=455168)
   5    3         TABLE ACCESS (FULL) OF 'T_MIDDLE' (Cost=39 Card=28447 Bytes=113788)
   6    2       TABLE ACCESS (FULL) OF 'T_SMALL' (Cost=2 Card=100 Bytes=400) 

我们看到,通过这两个Hints的联合使用,该查询首先对T_MAX和T_MIDDLE表进行HASH JOIN,再以这个结果集同T_SMALL进行HASH JION.

1.查询v$database获得

由于DBID在控制文件和数据文件中都存在记录,所以如果能够mount数据库就可以查询v$database视图获得. 

SQL> alter database mount;

Database altered.

SQL> select dbid from v$database;

      DBID
----------
3152029224

SQL>  

2.在nomount状态时

如果数据库配置了自动控制文件备份(Oracle9i),并且名称是缺省的,那么我们可以从自动备份文件获得DBID. 

[oracle@jumper dbs]$ cd $ORACLE_HOME/dbs
[oracle@jumper dbs]$ ll c-*
-rw-r----- 1 oracle dba 3375104 Dec 21 11:13 c-3152029224-20051221-00
-rw-r----- 1 oracle dba 3358720 Jan 21 14:03 c-3152029224-20060121-00
-rw-r----- 1 oracle dba 3358720 Jan 21 14:08 c-3152029224-20060121-01

这里的3152029224就是DBID.

而以下修改纯属无聊:

1.通过oradebug修改SCN

[oracle@jumper oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.4.0 - Production on Wed Dec 21 10:33:35 2005

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
With the Partitioning option
JServer Release 9.2.0.4.0 - Production

SQL> col a for 999999999999999
SQL> select CHECKPOINT_CHANGE# a from v$datafile;

              A
---------------
   107374358304
   107374358304
   107374358304

SQL> oradebug setmypid
Statement processed.
SQL> oradebug DUMPvar SGA kcsgscn_
kcslf kcsgscn_ [5000BC68, 5000BC88) = 00000019 0002F97F 00004979 
00000000 00000000 00000000 00000000 5000B948
SQL> oradebug poke 0x5000BC69 4 8
BEFORE: [5000BC68, 5000BC70) = 00000019
AFTER:  [5000BC68, 5000BC70) = 00000819

2.确认更改

SQL> select dbms_flashback.get_system_change_number a from dual;                A ----------------    8903467399681 SQL> oradebug DUMPvar SGA kcsgscn_ kcslf kcsgscn_ [5000BC68, 5000BC88) = 00000819 0002FA0C 00004A75 00000000 00000000 00000000 00000000 5000B948 SQL> SQL> alter system checkpoint; System altered. SQL> select CHECKPOINT_CHANGE# a from v$datafile;                A ----------------    8903467399867    8903467399867    8903467399867

3.此时无法正常关闭数据库

Oracle会检测到异常:

SQL> shutdown immediate;
ORA-00600: internal error code, arguments: [kfhsls_02], [20], [1], [], [], [], [], [] 

1.在Oracle9i及以上版本中

可以使用dbms_flashback.get_system_change_number来获得

SQL> select dbms_flashback.get_system_change_number from dual;

GET_SYSTEM_CHANGE_NUMBER
------------------------
                 2982184

2.在Oracle9i之前

可以通过查询x$ktuxe获得最接近当前系统scn值

 X$KTUXE-------------[K]ernel [T]ransaction [U]ndo Transa[x]tion [E]ntry (table)

SQL> select max(ktuxescnw*power(2,32)+ktuxescnb) from x$ktuxe; MAX(KTUXESCNW*POWER(2,32)+KTUXESCNB) ------------------------------------                              2980613

3.通过oradebug获取

以前在l2g32003的站点上看到使用oradebug获取SCN的方法,转引在这里:

[oracle@neirong oracle]$ sqlplus "/ as sysdba" SQL*Plus: Release 9.2.0.4.0 - Production on Wed Dec 21 21:04:24 2005 Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved. Connected to: Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production With the Partitioning, OLAP and Oracle Data Mining options JServer Release 9.2.0.4.0 - Production SQL> col a for 999999999999 SQL> oradebug setmypid Statement processed. SQL> oradebug DUMPvar SGA kcsgscn_ kcslf kcsgscn_ [1200BC68, 1200BC88) = 00000003 BA84F392 00071266 00000000 00000000 00000000 00000000 1200B948 SQL> select to_number('3BA84F392','xxxxxxxxxxxx') a from dual;             A -------------   16014177170 SQL> select dbms_flashback.get_system_change_number a from dual;             A -------------   16014177255 SQL>

Fri Dec 16 22:37:27 2005
Errors in file /opt/oracle/admin/conner/bdump/conner_smon_22817.trc:
ORA-00604: error occurred at recursive SQL level 1
ORA-00607: Internal error occurred while making a change to a data block
ORA-00600: internal error code, arguments: [4193], [1171], [1187], [], [], [], [], []
Fri Dec 16 23:28:40 2005
Errors in file /opt/oracle/admin/conner/bdump/conner_smon_22817.trc:
ORA-00600: internal error code, arguments: [4193], [1171], [1187], [], [], [], [], []

4193错误通常是因为恢复时redo与undo不一致所导致。

Oracle的解释如下:

  While backing out an undo record (i.e. at the time of rollback) we found a  transaction id mis-match indicating either a corruption in the rollback   segment or corruption in an object which the rollback segment is trying to  apply undo records on.

  This would indicate a corrupted rollback segment.

检查具体的Trace文件，可以发现类似如下错误：

*** 2005-12-16 20:54:53.496
ksedmp: internal or fatal error
ORA-00600: internal error code, arguments: [4193], [1171], [1187], [], [], [], [], []
Current SQL statement for this session:
UPDATE SMON_SCN_TIME SET SCN_WRP=:1, SCN_BAS=:2, TIME_MP=:3, TIME_DP=:4 
WHERE TIME_MP = :5  AND   THREAD = :6  AND   ROWNUM <= 1

在Oracle9i里，Oracle提供了一个内部事件，用以强制刷新Buffer Cache，其语法为:

alter session set events 'immediate trace name flush_cache level 1';

或者:

alter session set events = 'immediate trace name flush_cache';

类似的也可以使用alter system系统级设置:

alter system set events = 'immediate trace name flush_cache';

在Oracle10g中，Oracle提供一个新的特性，可以通过如下命令刷新Buffer Cache:

alter system flush buffer_cache;

我们通过试验来看一下刷新Cache的作用:

所谓的回收站，是一个虚拟的容器，用于存放所有被删除的对象。在回收站中，被删除的对象将占用创建时的同样的空间，你甚至还可以对已经删除的表查询，也可以利用flashback功能来恢复它， 这个就是flashback drop功能。

这个功能虽然可以极大的简化误drop导致的恢复操作，但是长时间的积累可能会导致大量的空间占用(虽然Oracle具有自己的清理机制)，很多时候我们需要手工介入去清理回收站。本文主要介绍清理回收站的几种方法.

 1.大量累计的空间占用

Connected to Oracle Database 10g Enterprise Edition Release 10.1.0.3.0 
Connected as SYS

SQL> col owner for a12
SQL> select owner,object_name,CREATETIME,DROPTIME from dba_recyclebin
  2  order by droptime
  3  /

OWNER        OBJECT_NAME                    CREATETIME          DROPTIME
------------ ------------------------------ ------------------- -------------------
COMMON       BIN$AHsQ+pi+Kb/gRAADumkBdQ==$0 2005-08-29:16:42:19 2005-09-11:15:36:17
COMMON       BIN$AHsQ+pi9Kb/gRAADumkBdQ==$0 2005-08-29:16:42:19 2005-09-11:15:36:17
PDA          BIN$AdEb4zqqUcTgRAADumkBdQ==$0 2005-09-05:10:31:01 2005-09-28:15:40:39
......
BJLAIS_RUN   BIN$BtkGRT0dSwfgRAADumkBdQ==$0 2005-11-30:10:54:07 2005-12-01:16:13:17
BJLAIS_RUN   BIN$BtkGRT0cSwfgRAADumkBdQ==$0 2005-11-30:10:54:07 2005-12-01:16:13:17

750 rows selected

SQL> 

2.不同用户在回收站的对象

SQL> select owner,count(*) from dba_recyclebin group by owner;   

OWNER                  COUNT(*)
-------------------- ----------
BJLAIS_RUN                   44
COMMON                        8
MMSBLOG                     618
MMSHAWA_RUN                   2
PDA                           8
RING_RUN                     70

6 rows selected.

3.我们可以指定删除某些特定对象

SQL> purge table common.T_SERVICE_CODE_INFO; Table purged.

4.指定清除某个表空间的所有回收站对象

SQL> purge tablespace common; Tablespace purged. SQL> select owner,count(*) from dba_recyclebin group by owner;   OWNER                  COUNT(*) -------------------- ---------- BJLAIS_RUN                   44 MMSBLOG                     618 MMSHAWA_RUN                   2 PDA                           8 RING_RUN                     70

5.以SYSDBA身份可以清除所有回收站对象

SQL> purge dba_recyclebin; DBA Recyclebin purged. SQL> select owner,count(*) from dba_recyclebin group by owner;   no rows selected

6.禁用recyclebin

我想到的一个方法是,通过查询v$version视图来得到:
1.Windows平台的输出

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.6.0 - Production
PL/SQL Release 9.2.0.6.0 - Production
CORE 9.2.0.6.0 Production
TNS for 32-bit Windows: Version 9.2.0.6.0 - Production
NLSRTL Version 9.2.0.6.0 - Production

2.Linux平台输出

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.4.0 - Production
PL/SQL Release 9.2.0.4.0 - Production
CORE 9.2.0.3.0 Production
TNS for Linux: Version 9.2.0.4.0 - Production
NLSRTL Version 9.2.0.4.0 - Production

3.Solaris平台的输出

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
PL/SQL Release 9.2.0.4.0 - Production
CORE 9.2.0.3.0 Production
TNS for Solaris: Version 9.2.0.4.0 - Production
NLSRTL Version 9.2.0.4.0 - Production

4.AIX平台的输出(感谢brucewoo提供的AIX上输出)

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.5.0 - 64bit Production
PL/SQL Release 9.2.0.5.0 - Production
CORE 9.2.0.6.0 Production
TNS for IBM/AIX RISC System/6000: Version 9.2.0.5.0 - Production
NLSRTL Version 9.2.0.5.0 - Production

5.HPUX上的输出(感谢tom.shew的提供)

SQL> select * from v$version;

BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.6.0 - 64bit Production
PL/SQL Release 9.2.0.6.0 - Production
CORE 9.2.0.6.0 Production

TNS for HPUX: Version 9.2.0.6.0 - Production
NLSRTL Version 9.2.0.6.0 - Production