最近用了一次DB2, 感觉同Oracle还是有一定差距。

turbo_c

你能解释为何开发报表打印程序的时候， 要针对每种不同的打印机专门写不同的DDS 的 Form 呢？
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你们买不起AS/400支持的打印机,用windows支持的,你就只能用不同控制串加到splf,谁叫你们穷呢,只要是as/400支持的打印机,不同的型号,也只需要一个格式.捷达的轮子,装在法拉利上能好使吗?

turbo_c

不错 RPG的运行效率高，可是你IBM 不要把AS400 上的DB2也统称作UDB , 好吗？
如果你只适用于RPG,那么请滚回到RPG的世界里去吧，不要在Java圈子里吹牛了！
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你的破pc可以上网,而as/400还不能上网,是不是你的破pc比AS/400还牛B啊?你这种SB也就懂个java,做做非核心的开发大学生刚毕业出来就可以抢你的饭碗,懂吗SB,招行的一卡通在db2/400,信用卡在db2/zOS上,网银不是跑得好好的?你没本事而已

czzhao

Just off the Top of My Heado -- some features Oracle have but UDB doesn't:

1. Truncate table

2. Block level recovery

3. Table range partitioning  -- udb is trying to catch this up in Viper, but this feature has already been around in Oracle for a decade.  

4. Oracle RMAN is very robust  on backup/reocovery. However, I have had problems while trying to backup a db2 udb TB level database with RUNSTAT runing.  IBM support confirmed this is a bug.

5. I backup a 2 TB Oracle database with 5.5 hours through TSM LAN-Free, but UDB takes 17 hours to backup 1 TB db2 database with same TSM settings.

6. Adding a containter to a db2 large tablepspace, the rebalancing really piss me off.

7. You can't really compare db2 HADR with Oracle's RAC+DATAGUARD.  IBM stole HADR from Informix, but you don't  seriously consider this as a DR solution. HADR can't even replicate stored procedures.  This is no kidding.  Please see following thread if you have interests.

Technical Comparison of Oracle Data Guard vs. IBM DB2 HADR
http://www.oracle.com/technology ... /DataGuardHADR.html

8. Gartner & IDC survey shows worldwide RDBMS market for 2005, Oracle sat on the biggest slice—48.9%,  IBM 21.4%. This more or less tells the Oracle popularity.

Oracle Eats the Database Market—Again
http://www.eweek.com/article2/0,1895,1967358,00.asp
...............
etc etc.

I am trying not be biased.   I support both Oracle and DB2 UDB for a major Canadian Bank.  All are TB level databases.   Oracle is much more poplure than db2 here.  As my shop is a bank, we still have lots of db2 applications.

I've heard db2 on ZOS is very solid then udb,  unfortunately I have not got chance to try it out.  Just like to share some of my experiences with you guys.  Don't want any db2 believers get offened by my comments.

wangzhonnew

hehe, there are ways to truncate tables using load from empty file, and table range partition is supported in v9.
usually db2 need carefully tunning to make the performance best~~~
there are several solutions for high avaliability, hadr is one of them. hadr is built on log shipping so definitly SP cannot be shipped (they are treated like 2 separated databases), if you want you can use HACMP for ha solution, which is sharing disk and the SP problem will no longer persist....

and yes, the market of oracle is much better than db2, so db2 still have a long way to go, at least on the user interface level (include api, sp, gui, debugger.....)

ryan76

争论出火花了，呵呵

楼上和楼上的楼上都来自Toronto只是大小写不同

czzhao

I knew the load from /dev/null trick.  Truncate a table is just a very simple thing for many other database, why db2
wants to give users the alternative?

Oracle data guard is also built on log-shipping technology just as db2 does, but Oracle can replicate EVERYTHING. If you
can bear with DB2 HADR with no SP replication, what about CLOBs/BLOBs?

Speaking of HACMP, Some of financial applications require 5 nines avaliability - 99.999%. That means 5 minutes unplanned
outage for a year. Because of this strict requirement, we have to choose Oracle RAC over IBM HACMP.

For DBMS market shares, an IBM sales told me last year at a IBM workshop that 65% databses running on Power5 pSeries servers
are Oracle.  Oracle does even better on Linux: 82% oracle vs 17% db2.

Anyway, I really hope db2 can get better and better which can make my day-to-day dba work easier.  To be honest, I feel
a little disappointed on Viper -- 5 years non-stop development since v8 with IBM 750 developers across 30+ cuntries.  

I thought IBM could do a much better job.

wangzhonnew

oops.. i don't know anything about oracle, really curious how oracle replicate lob (hadr can replicate up to 1GB LOB) and SP? could you give some detailed explianation?
i know this question kinda out of topic of this thread, just want a quick answer other than open a new ticket in oracle forum

and you are very correct, the market always can reflect "what the users want", in this case db2 has some weakness than his competitor and i definitly agree with it. so i will never say "db2 is the best".

however i also do not agree "oracle is better than db2". he can say "from my expierence, or in program development point of view, oracle is easier to use than db2". just like algorithm, you cannot improve the performance without lossing anything. it's a trade off....
shared nothing arthitecture may bring some inconvinience in the business but at other hands it can bring better performance (also easier to manage, coz each partition is treated exactly like a single database, except sharing trace and fcm buffer with other nodes) or something like that....

czzhao

Oracle treats SP/LOB changes as logical changes, that goes to redo logs as well. Then archiver(or log writter) ships the redo logs to Stadnby synchronously or asynchronously and apply it from there.  It doesn't have size limit on the LOB changes.  However, if you want to know everything about Oracle Dataguard.  I would say tahiti.oracle.com is the best place.  Tahiti,  the place of my  dream vacation.

Prior to Oracle8i,  it is called Standby database.  Dataguard is just a synonym of automated Standby database.  Oracle DataGuard used to have some limits on physical db structure changes -- for example, you add a new datafile (containter in db2) to a tablespace on Primary, you also have to do the same thing on Standby.  Since 9i, this limit has been removed.

I never say "Oracle is the best" either.  Just from a DBA perspective, which one can make my life lot of easier.  Everyday, feels on vacation in Tahiti -- that is my dream.

Oracle or DB2?  Personally, I probably weigh more on job security than a  matter of interests.  Just make a living, that is it.

I visit this db2 forum daily, try to get updates and learn from you guys.  Always show my respects.  I also find lot of more Oracle Tops on Itpub -- that is the main reason I drop by everyday.  

If you are in Toronto, we may have a chance for a private chat.

wangzhonnew

hehe it's nice to talk to someone who's knowledgeable in both oracle and db2 side
but unfortunatlly i'll go back to school after next week
hope i can find a job in toronto after graduation and then we may have a chance for a chat
have a nice weekend dude

turbo_c

1. Truncate table
知道clrpfm是什么吗?

2. Block level recovery
rstlib比你oracle 的import效率高得多