I’ve just been browsing through a subdirectory on my laptop that has survived many migrations from machine to machine over the years – even though some of the material needs programs that probably don’t exist any more.
This slide, from a presentation I gave at the UKOUG annual conference in 1996, raised a wry smile. The title of the presentation was “Fact, Folklore, or Fairy-table” – possibly the first ever “Mythbuster” presentation on the Oracle scene. The title of each slide declared a popular belief, and the rest of the slide commented on the sense or (usually) lack thereof in the belief.
The notes on this particularly slide show that I was talking about Oracle 7 at the time but I remember explaining this particular concept to the DBA at one client site shortly after 6.0.33 went into production.
Amazingly you can still find questions on the internet about tablespace fragmentation – even though the topic should have been done to death years ago.
This is great! Can you post the whole thing? Are there any you would disagree with now? Were you making assumptions about different sized data or volatility per tablespace?
Comment by joel garry — July 1, 2008 @ 10:13 pm BST Jul 1,2008 |
Joel,
The presentation was 45 minutes, and apart from the introduction, background and conclusion there are only seven slides. That makes the slides very sparse talking points – so I’m not keen to post the presentation as someone’s bound to misinterpret it. (How long do you think it’s going to be before someone cites the title from this slide without reading the rest of the note ?)
The comments I chose to discuss were:
In outline, omitting a few of the details and caveats, the comments that went with them were along the lines of:
The closing slide was a bit of a classic, it said:
If I were to present that last slide today, I’d probably change it to “If it’s supposed to make a big difference …”.
Comment by Jonathan Lewis — July 2, 2008 @ 10:26 am BST Jul 2,2008 |
Can’t remember the precise date, but Dave Ensor came out to Oz in the mid 90’s and did a similar talk – something like ’20 stupid things people do’….As I ticked off around 17 of the 20 as things I was regularly doing, I decided it might be time to learn a little more :-)
Comment by Connor — July 2, 2008 @ 2:44 pm BST Jul 2,2008 |
Humm… is that enough material to demonstrate correlation between “Buffer hit ratio” and “tablespace fragmentations”?
Comment by Polarski Bernard — July 3, 2008 @ 7:41 am BST Jul 3,2008 |
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