How (not) to Lose Your AudienceChris LawsonAvoiding Big Blunders

Whats the Issue?Really smart people often do really poor presentations.Sometimes even the featured speaker falls into this trap.This makes it tough for the audience to learn new ideas.It also wastes time.

Why Should I Care?Your presentation affects how people think about you.Fair or not, you gain or lose credibilityA great talk will be remembered for years.An unprepared speaker will likely not be invited back. Your ideas will be forgotten.Not the best use of time.

The Good News Great presentations have little to do with your actual speaking ability.Most of it has to do with preparation.Preparation can be time-consuming, but the Payoff is huge.

THIS IS HOW YOUR LISTENERS WILL REACT TO A GOOD PRESENTATION

BUT--YOU CANT WIN EM ALLPhoto courtesy of: Guy sleeping behind obama at graduation"

2 Points to Remember Great speakers arent the smartest; they are the best prepared.

Consider what the audience will see

Blunder # 1

Failing to check-out room & equipment

How Can I Tell Im Losing the Audience? Here are some easy ways to see youre losing it.

How Can I Tell Im Losing the Audience? It may take keen skill to spot when youre beginning to fade . . .

These Guys Need Help

How Rude!

CASE STUDY:

How Can I Tell Im Losing the Audience?

Be Alert to Subtle SignsPhase 1: Boredom Note Glazed EyesDo I get 17 or 18 weeks vacation?

Watch for Subtle SignsPhase 2: Restlessness Vacant stareI didnt know we DBAs were so boring

Watch for Subtle SignsPhase 3: Loss of Consciousness Not very alert, beginning to drool

Watch for Subtle SignsPhase 4: Coma (or death) No pulse

Blunder # 2The Cram Method

Show slides with so much information no one can possibly comprehend it.

Corollary: Try to impress your audiencethe more information the better!

ResultsYou have lots of cool resultsNo one can read thisNo one can understand this

Graphs are your friend

Fastest Database - TPC-H SizeDatabaseHardwareCPU/OSCost300GOracle 10gHP/Proliant8/RHEL4524K1TOracle 10gHP/Superdome64/HP UX4.0M3TOracle 10gSun/E25K 72/Solaris5.8M10TOracle 10gSun/E25K72/Solaris5.8M

The performance metric reported by TPC-H is called the TPC-H Composite Query-per-Hour Performance Metric(QphH@Size). The TPC BenchmarkH (TPC-H) is a decision support benchmark. It consists of a suite of business oriented ad-hoc queries and concurrent data modifications. The queries and the data populating the database have been chosen to have broad industry-wide relevance. This benchmark illustrates decision support systems that examine large volumes of data, execute queries with a high degree of complexity, and give answers to critical business questions.Source: www.tpc.org (As of April 19, 2006)

Some Actual Slides

I am not jokingthe following are real slides from recent speakers

Do crosstab from RC_BACKUP_PIECE view.Make anything before 4PM part of previous overnight run: CREATE OR REPLACE VIEW ucsc_bkup_trend_insert_vw (...column aliases...) AS SELECT CASE WHEN to_char(p.START_TIME,'HH24') < 16 THEN trunc(p.START_TIME - 1) ELSE trunc(p.START_TIME) END AS bkup_date, sdl.SERVER_NAME, d.name, p.device_type, nvl(max(CASE WHEN backup_type = 'D THEN p.ELAPSED_SECONDS END),0) AS LVL0_secs,nvl(max(CASE WHEN backup_type = 'I' THEN p.ELAPSED_SECONDS END),0) AS LVL1_secs, nvl(max(CASE WHEN backup_type = 'L' THEN p.ELAPSED_SECONDS END),0) AS ARCH_secs, nvl(max(CASE WHEN backup_type = 'D' THEN p.BYTES END),0) AS LVL0_bytes, nvl(max(CASE WHEN backup_type = 'I' THEN p.BYTES END),0) AS LVL1_bytes, nvl(max(CASE WHEN backup_type = 'L' THEN p.BYTES END),0) AS ARCH_bytes, p.START_TIME, p.COMPLETION_TIMEFROM rc_backup_piece p, rc_database d, ucsc_server_db_list sdl [...]Runtime Trends

Identifying Granules of Parallelism during scans in the plan

Metadata Reporting: Compression RatioCOMPRESSION_RATIO column is in 10 _summary and _details views, but these are primarily intended to be used internally by Enterprise Manager. Before finding that caveat, I had found results to not trust RC_BACKUP_SET_DETAILS --- good to avoid. In following chart, (10.2.0.2 for testing), Input Bytes is same for Level 0 and 1, so calc is from total DB used space. Level 1 ratio is distorted.The BDF table in RC_BACKUP_DATAFILE view knows about Block Change Tracking, and has count of blocks scanned, so a better ratio could be calculated.

Please Take this Survey

Keynote Speaker SlideTwitter.comAmazon EC2Cuil.comApple iStore 2008Google GmailWolframAlphaCompany XYZKeynote presentationOct, 23, 2009

What do You Think of this?The fastest execution plan usually is the one that touches the fewest rows, and this, in turn, is the one that discards the fewest rows, and that discards those rows that must be discarded the earliest, before wasting work on unneeded joins. This usually starts with the best filter condition (the one reaching the smallest fraction of its table), and reaches every large table with the fastest path (usually a filter-column index for the first table and nested loops to a join-key index for the later large tables).The goal is normally a query that runs in minutes, at the most, without requiring parallel threads.

Reaction to Prior SlideI believe this person is inept.This guy is trying to bamboozle me.This presentation was thrown togetherThis is going to be really boring.Is he going to read every line? (Ans: Yes, he did.)Im not inviting this guy to my party.My reaction: I left after 5 minutes.

These reactions might mislead you, because . . .

The Lesson In actuality, the author of the messy slide is a genuine performance expert.About 13 years ago, I learned a great tuning technique from his writings.I use his technique nearly every day.

Moral: His presentation worked against him instead of attesting to his skill

Lets Try a RedesignHeres the Original . . .

Tips on Performance TuningThe fastest execution plan usually is the one that touches the fewest rows, and this, in turn, is the one that discards the fewest rows, and that discards those rows that must be discarded the earliest, before wasting work on unneeded joins. This usually starts with the best filter condition (the one reaching the smallest fraction of its table), and reaches every large table with the fastest path (usually a filter-column index for the first table and nested loops to a join-key index for the later large tables).The goal is normally a query that runs in minutes, at the most, without requiring parallel threads.

Heres the Redesign. . .

Tips on Performance Tuning For good execution plans touch as few rows as possibleFilter-out rows as early as possibleStart with the best filter conditionOptimize first--use parallelism last.

Lets try an example.Try Replacing lots of text with a Picture

Example with TextThere was once a very small software company that had a small government contract. The founders had some good ideas, but not a lot of money. They were smart, but some of them didnt even have college degrees. To make things worse, some of them were sort of nerdy, and were not too good at social skills. Some of them even wore pocket protectors and put lots of felt-tip pens in their pockets. Nevertheless, they struggled, worked hard, and made lots of money. Today the founders are very famous and rich. If you work hard, you too can be like them.

Do you recognize any of these guys . . . ?Example with Picture

Oracle CorporationOne-year AnniversaryEd Oates, Bruce Scott, Bob Miner, and Larry Ellison

Blunder # 3Dull, Boring Monotone

Blunder # 4Make slides that cannot be read

Corollary: Use colors that are scary

Chilean ExportsFresh fruit leads Chile's export mix - Chile emerges as major supplier of fresh fruit to world market due to ample natural resources, consumer demand for fresh fruit during winter season in U.S. and Europe, and incentives in agricultural policies of Chilean government, encouraging trend toward diversification of exports and development of nontraditional crops - U.S. Dept. of Agriculture, Economic Research Service Report Chile is among the developing economies taking advantage of these trends, pursuing a free market economy. This has allowed for diversification through the expansion of fruit production for export, especially to the U.S. and Western Europe. Chile has successfully diversified its agricultural sector to the extent that it is now a major fruit exporting nation. Many countries view Chile's diversification of agriculture as a model to be followed. Meanwhile, the U.S. remains the largest single market for Chile's fruit exports. However, increasing demand from the EC and Central and East European countries combined may eventually surpass exports to the U.S., spurring further growth in Chile's exports. If youve read this far, your eyes probably hurt and youve been reading this tedious long-winded text instead of listening to me. Im insulted- cant you see Im doing a presentation up here? Look at me! Congratulations, however, on having such good eyesight.

Do You Remember this Point? Consider what the audience will see

At Vision-Loss ConferenceSpeaker showed complex slide with small font, and asked,Can everybody see this okay?

Have mercy on the poor folks trying to read . . .

Beginner MotorcyclesMy personal favorite: the Suzuki SavageLight weight (~380lbs)Adequate power (650cc engine)Low seat height fits most riders

Mommy, my eyes are burning!Can you look at this for 45 minutes?Colors look different on every LCD projectorColors look different between transparencies and projector

If printing slides, save ink by choosing white background.Mommy, my eyes are burning!

Use PowerPointDazzle them with 256,000,000 colors!Clich templates!Sound Effects!Annoying transitions!Import video and animations that won't workPut an annoying header and footer on every slideTerrible Presentations 16/17

Summary: Big BlundersFailure to prepare the roomOverly complex slidesMonotone presentationUnreadable slides

2 Points to Remember Great speakers are the best prepared speakers

Consider what the audience will see

For Further Reading on What You Should do

Rich NiemiecConsistently rated #1 presenterSee: Giving Winning Presentations Collaborate 2009