DBA Best Practices

You can’t give that responsibility to someone who doesn’t know how to handle it.. DBA is a roleLike a policeman or teacherUnstated responsibilities, expectations Most people don’t know w

Oracle DBA Best Practices

Dennis Williams Senior Database Administrator Lifetouch, Inc.

About Me

TCOUG member since 1990

8 years only DBA at Lifetouch, Inc.Lawson Software Database

Research EngineerConsultant - FingerhutControl Data

Contact me at dwilliams@lifetouch.com

There’s no asset more important than a company’s data You can’t give that

responsibility to someone who doesn’t know how to handle it

Malcom Fields, CIO

Time - Until lunch is readyLeft-brain portion - tech IssuesRight-brain portion - softer issuesDatabase audit form

75,610 DBAs

U.S Bureau of Labor Statistics in

2003 began tracking the IT workforce

6.46% unemployedThere are 797,445 Software Engineers (5.3% unemployed)DBA supports about 10

developers

Where do DBAs come from?

Schools don’t offer a degree

Developer DB developerSystem Administrator

DBA is a role

Like a policeman or teacherUnstated responsibilities, expectations

Most people don’t know what a DBA does

DBA time breakdown

22% Fire Fighting33% Monitoring12% Perf Tuning / Change Mgt.33% Development Support

0% Planning for growth0% Backup & Recovery Planning0% Learning

Koopman

Keep a personal time log - 1 weekLearn your time distribution

Target improvementsStudy time management

Levels of Oracle DBA

Rookie Veteran Expert

TCOUG No time Member,

attends reg.

On the board Studies Admin.

classes

OCP, books OCM,

author, conferences Online

forums

No time Lurks, asks Answers

questions New Oracle

features

Uses any feature

Wary of new feature

Creates tests to find problems

Misconception: you are an expertMultiple choice, so simple

questionsBroad, not deepCareer benefit - can’t hurtCan help you go deeper in Oracle

Production Support DBA

Keep it running

“shepherd / farmer” personalityWhere best practices really make a difference

The hero isn’t the DBA that battles problems through the weekend,

but the one that avoided the problem

Application DBA

Supports a business critical app like Oracle Financials, SAP,

Peoplesoft, LawsonProduction support, some dev.Key skill: understands how the app Interacts with Oracle

Can’t self-studyCaution: Vendor doesn’t operate databases in production

Consultant DBA

Fastest way to get expertiseVaried work opportunitiesUnderstand economic cycles

Backup is Job #1

Ensuring data is never lostDon’t trust an untested backup configuration

Be ready to perform any type of recovery at any time

Communicate vulnerabilities, recovery times to managementArchivelog mode by default

Cold or Hot backups, which best fits your environment

Export: the DBAs friend

Enhance recoverabilityEasy to recover a single table, avoid full recovery

Checks block corruptionTeach your developers to request special exports

Validate, no errors, Unix strings command, last line should be EXIT

security, data sensitivity

Making it work

Dev to Prod

ITIL

3 environments - test/stage/prodClone DB from backup

Developers provide scripts to change production

Simple application login testAlways have a backout plan

Is this change worth the possible

Oracle Performance Tuning - Types

SQL Statements - explain plan, tkprof, 10053 events

Application disasters - 10046 trace, Cary Millsap (TCOUG Hotsos

seminar)Proactive tuning and hanging - STATSPACK, utlestat/utlbstat

You must know what your server is doing.

Not your Dad’s Oracle tuning

Rules of thumb, ratios to mathematical foundationsCounts to measured times in microseconds

Aggregate by instance to process details

V$ tables are either too summarized or point-in-time

Goal of tuning

What matters to the business userGood chance to sell value

End-to-end analysisDBA must prove innocence

There is nothing so useless

as doing efficiently that which shouldn’t be done at

F DruckerUse LMT, uniform extents, vs

rebuildUse autoextend vs monitoring

Appl quality requirementsWhat are others saying? Metalink

Knowledgeable if not authorized

Troubleshooting

Never worked? Check installationWorked earlier, doesn’t work now? What changed?

Intermittent? (worst kind) How does it vary? With time, system load, hardware?

From Oracle Networking 101 by

Key: What is essential?

Don’t document what can easily be figured out

Keeping up-to-date is the crucial aspect

Obsolete documentation is treacherous

Self-documenting where possible

Data architect is a DBA career pathParticipate in initial design where your leverage is large

Tech Learning List

Application interface methods - Microsoft, Java, OCBC

Server tuningStorage methods and options, strengths and weaknesses

Effective communication proceeds from shared knowledge

When you can’t get experience

Be aware of the limitsWell-defined area? (books?)Can earn credentials?

Area where you can gain significant knowledge with a reasonable effort?

Average experience of competitors

Know your learning style

Left-brain vs right-brainFour primary learning styles:

Visual (diagrams) Auditory (reading) Tactile (hands-on) Kinesthetic (body)

Your manager’s learning style

People Skills

Few people besides a DBA understand what a DBA doesThis makes it hard to communicate your value to the organization

People don’t mind paying for what they value, but resist paying for what they don’t consider valuable

If your manager is a DBA, less

We are the hero of our own movie,

we justify ourselves, never the bad guy

Really care about the people you

How to avoid problems

Many bad reactions stem from a lack of warning

Emotions play a large role in decision-making

Work hard to warn people ahead of time of what will be coming

Don’t know why? Assume stupidity

A DBA appreciates a heads-up, why shouldn’t others?

When you’re wrong, admit it, quickly

Any man worth his salt will stick up for what he believes right, but it takes a slightly better man to acknowledge instantly and without

reservation that he is in

Jackson

Feeling no controlConstant interruptionsDBA syndrome - responsible for everything, control nothing, nobody understands

You hear yourself saying “nobody appreciates me”

Antidote: study stress control, exercise

That Problem Person

Sandwich / Oreo approach by Rachel Carmichael

1-on-1 outside the officeBegin with a complementMake statements addressing the problem, starting with “I” - “I feel”,

“I think”, “what I see is” ListenWrap with team-building “we can work together on this”, “I need your help”

End with a nice complement

Database Audit Form

Periodically audit each databaseChecklist for problems

Form is terse, so I included a sheet describing the purpose of each

check