Dontcheff

Archive for November, 2011|Monthly archive page

DBA: Don’t Bother Asking

In DBA on November 23, 2011 at 17:05

To all of you from all of me what DBA can mean and be!

DBA: FlyDBA.com

DBA: Delaware Bankers Association

DBA: Double Barrel Ale

DBA: Design Business Association

DBA: Disc Brakes Australia

DBA: Doing Business as Brooklyn

DBA: Differently-Abled Business Association

DBA: Dual Band Amplifier

DBA: Detroit Batting Academy

DBA: Dallas Business Association

DBA: Double Barrel Air Pump

DBA: Deter’s Beer Asylum

DBA: Doctor of Business Administration

DBA: Defense Base Act

DBA: Digital Broadcasting Australia

DBA: Dollar Bill Acceptors

DBA: Deaf Basketball Association

DBA: Dumb But Adorable

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Beautiful mind: DBA Work Motivation

In DBA on November 12, 2011 at 17:01

Theodore Roosevelt: Far and away the best prize that life has to offer is the chance to work hard at work worth doing.

Margaret Thatcher: I do not know anyone who has got to the top without hard work. That is the recipe. It will not always get you to the top, but should get you pretty near.

Woody Allen: I don’t want to achieve immortality through my work. I want to achieve it through not dying.

During Oracle OpenWorld 2011, Paul Vallee (Founder and Executive Chairman at The Pythian Group) and Alex Gorbachev (Chief Technology Officer at The Pythian Group) organized a DBA Manager meeting where (probably) the most interesting topic discussed was what motivates DBAs.

The internet is full of articles, debates and research done on work motivation but this one is worth watching:

Interesting enough, same holds for DBAs: independence, mastery and purpose are the key motivators. All combined, they lead to self satisfaction from the DBA profession and although money might always come in between, it is by far a very short term motivation factor. Although, note that for about half of the population money is the primary motivator to perform the job properly.

1. Independence

Autonomy for the DBA is crucial in IT. Those DBA managers who micromanage their DBAs are doomed to failure. A DBA Manager should trust his/her DBAs as they should likewise trust him/her. And this would be the ideal situation.

2. Mastery

Wonder why so many people have blogs, website and answer questions in database forums? And they do it for free. Even writing a book is never for financial benefits. It is the hidden will inside us to develop skills and share them with others.

3. Purpose

Every DBA has a purpose in his career: one purpose or more than one purpose, a small one or a big one. And the purpose might change the direction of his/her DBA’s career. Call it a career goal, an internal motto. And of course, I also have one.

Another interesting concept in the DBA profession is that of the over-motivated Cowboy DBA: a person who with very good intentions screws up the production system quite quickly:

– use a new init.ora parameter (or an underscore one) in production without checking all bugs related to that parameter or test it in advance
– restart a production database in order to fix something and what that thing was remains usually a mistery
– kill all or some user sessions in production to “release” locks:

select 'alter system kill session '''||sid||','||serial#||''';' 
from v$session where username = 'PROD_USER';

– run “rm -rf *” without additionally typing “pwd”

Let me quote Don Burleson: “As every DBA knows, all developers are secretly studying database administration”. His addition is “and actively plotting to take their jobs” while mine would be “and are potential cowboy DBAs”. That is why DBAs do not usually give developers access to Production?

The Newest init.ora Parameter in the Oracle Database

In Database tuning, DBA, Init.ora, Oracle database on November 6, 2011 at 14:18

Altogether there are 347 init.ora parameters in Oracle Database 11.2.0.3. Looking into all documented and undocumented parameters in 11.2.0.3, we witness a high number: 2752.

11.2.0.3 does not sparkle with any fancy features and no one is expecting it to but there is one new init.ora parameter added by Oracle: awr_snapshot_time_offset.

Why is it needed? The answer is very clear in case you have a server with several databases running on it. Consolidation has been fashionable for the past decade and many scattered corporative databases have perched on the same computer.

You might have observed those spikes on the top of every hour when all the AWR snapshots are taken. How do you avoid this, i.e., say you have 12 databases on the server and you want snapshots taken on hour bases but within 5 minutes difference for every database?

Quite simply with awr_snapshot_time_offset by setting it for n*300 (seconds) for every n:th database (n = 1..12).

The documentation of awr_snapshot_time_offset gives additional details for the parameter.

And finally, here is how one can search for the values of certain parameters, for example Bloom filter related:

select a.ksppinm name, b.ksppstvl value 
from x$ksppi a, x$ksppcv b 
where a.indx = b.indx 
and a.ksppinm like '%bloom%';