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Philosophy – 14
Paraphrasing Yogi Berra: “It ain’t committed until it’s committed.” If you’re wondering why it’s worth remembering this odd comment – it addresses the (commonly asked) question: “does the redo log...
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Ambiguity
“There is no space problem.” If you saw this comment in the middle of a thread about some vaguely described Oracle problem, which of the following would you think was the intended meaning: There is a...
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Philosophy 15
If you run a query that is supposed to return one row from a large table, and there’s a suitable index in place you would probably expect the optimizer to identify and use the index. If you change the...
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Theory
Here’s a quote that says it all: Dr Joseph Lykken of Fermilab – in response to some (negative) results from the Large Hadron Collider that suggest the simplest form of SuperSymmetry is wrong: “It...
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Proof
Here’s a wonderful lesson from Cary Millsap – be very careful if you ever want to sell him anything – that reminded me of a Powerpoint slide I had produced for a presentation a few years ago. It took...
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Philosophy 17
You need to understand the application and its data. A recent request on OTN was for advice on making this piece of SQL run faster: delete from toc_node_rel rel where not exists ( select * from...
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Philosophy 18
A question I asked myself recently was this: Which is the worst offence when publishing an article about some feature of Oracle: Saying something does work when it doesn’t Saying something doesn’t work...
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Philosophy 19
We’ve reached that time of year (Autumn, or Fall if you prefer the American term) when I’m reminded that tending a garden is like tending an Oracle database. This is a picture of the oak tree on my...
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Philosophy 20
It’s important to revisit the questions you think you’ve answered from time to time. You may find that your previous answer was wrong or incomplete; you may find that looking at your past answers may...
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French Philosophy
From Mohamed Houri, here’s a French translation of all my “Philosophy” notes to date.
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Philosophy 21
I’ll be buying the tickets for my flight to Seattle and Kaleidoscope 14 some time tomorrow. The cut-off date on my credit card bill is today, so if I get the tickets tomorrow I won’t have to pay for...
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Philosophy 22
Make sure you agree on the meaning of the jargon. If you had to vote would you say that the expressions “more selective” and “higher selectivity” are different ways of expressing the same idea, or are...
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Testing
This post is a 100% copy of a message that Tanel Poder sent to the Oracle-L mailing list in response to a thread about the performance of SSD. It’s not just a good answer to the question, it’s a...
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Expert
I was sent the following email a few years ago. It’s a question that comes up fairly frequently and there’s no good answer to it but, unusually, I made an attempt to produce a response; and I’ve...
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Never …
From time to time a question comes up on OTN that results in someone responding with the mantra: “Never do in PL/SQL that which can be done in plain SQL”. It’s a theme I’ve mentioned a couple of times...
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Block Names
There are a number of tiny details that I can never remember when I’m sketching out models to test ideas, and one of those is the PL/SQL block name. Virtually every piece of PL/SQL I write ends up with...
View ArticleWhy Bother
This note comes to you prompted by “Noons” in a recent twitter exchange In response to a complaint by Lukas Eder about having to educate people in 2016 that there is no (performance) difference between...
View ArticleRTFM
Imagine you’re fairly new to Oracle and don’t have a lot of background information at your fingertips; then one day someone tells you to read the manual pages for the view dba_free_space. Look...
View ArticleAssumptions
As the years roll on I’ve found it harder and harder to supply quick answers to “simple” questions on the Oracle-L list server and OTN/ODC forum because things are constantly changing and an answer...
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