Oracle-L: Re:RE: Good DBA vs. Bad DBA

From: <dgoulet_at_vicr.com>
Date: Thu, 09 May 2002 09:47:14 -0800
Message-ID: <F001.0045CFF0.20020509094714@fatcity.com>

Jared,

Sounds like we've got a newbe on the list, and a pretty green one at that.

Databases do not crash on their own, they are caused. Therefore a good dba looks forward to the reasons for a database crash and does what is necessary to prevent them.

Now I've also got some real good SA's who likewise do not appreciate system crashes so we've put a lot of time & effort into crash proofing things as much as possible. That means servers with redundant CPU's, power supplies, etc... Full disk mirroring with three not two mirrors. Connectivity software and scripts with our UPS system so we shutdown nicely before power runs out. And on top of all that a standby generator. So the servers and disks are fully protected.

On the database side, control files are mirrored to different drives, along with redo logs. Backups are done regularly and are checked. Archived redo logs are kept on off-line media for as long as the backups and then some. Recoveries get occasional practice. Users do not own application specific tables. Passwords are changed periodically. Databases are monitored 24 hours a day and dba's and sa's get alerted when things are not right. Alter logs get daily scans. The result here has been no database crash for the last three years. The last one occurred due to a power problem. When we got together to figure out what happen & what to do about it the UPS software was recommended and bought, and the standby generator became a reality. Last power interruption we had, the DB's did not even know something happen.

The end of this is that crashes have causes. If yours crashes find out what caused it and do whatever it takes to prevent it from reoccurring in the future. In the mean time, try doing a cause & effect analysis. Look at the hardware and OS your running on. What would happen if they failed? Why would they fail? Can you do something about it? Look at your DB configuration. What could fail? What can you do to prevent it? My first DB crash occurred when the disk drive where my control file & system tablespace resided failed. They no longer reside together and there is always more than one control file. A mirrored system tablespace is also a MUST have item.

Dick Goulet

____________________Reply Separator____________________
Author: Jared.Still_at_radisys.com
Date:       5/9/2002 9:14 AM

Huh?

"Sinardy Xing" <SinardyXing_at_bcs-ach.com.sg> Sent by: root_at_fatcity.com
05/09/2002 12:48 AM
Please respond to ORACLE-L

        To:     Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
        cc: 
        Subject:        RE: Good DBA vs. Bad DBA

Do you guys still afraid of database crash ? Or I just too sensitive or no confidence

-----Original Message-----
Sent: 09 May 2002 08:18
To: Multiple recipients of list ORACLE-L

Dennis, I think you nailed it.

I was a skeptic before I was a DBA.

Jared

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INET: Jared.Still_at_radisys.com

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