Opening Menu
Welcome
This is the entry point for the Oracle Scratchpad - a static page that indexes all the ‘non-blog’ pages on this and other sites.
If you want to use the more traditional blog entry point you can bookmark this URL for ordinary postings. This is also the URL for the page referenced to the right called All Postings.
Towards the end of this document there are some suggestions about leaving comments. Some of the usual html tags do not work as expected in the comments editor - this is a side effect of the theme I chose, which seems to be the only one that makes code extracts look nice. If you remember to use these guidelines it will make your points more readable for other users.
Contact Details:
Email: jonathan@jlcomp.demon.co.uk
Homepage: www.jlcomp.demon.co.uk
Office Phone: +44 (0)7973 188785
A few Inspirational Thoughts:
Stephen Hawking: The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.
Erwin Schrödinger: Thus, the task is, not so much to see what no one has yet seen; but to think what nobody has yet thought, about that which everybody sees.
Sir Peter Medawar: (On “The Phenomenon of Man”): Yet the greater part of it, I shall show, is nonsense, tricked out with a variety of metaphysical conceits, and its author can be excused of dishonesty only on the grounds that before deceiving others he has taken great pains to deceive himself.
Albert Einstein: We can’t solve problems by using the same kind of thinking we used when we created them.
Richard Dawkins: Science has no methods for deciding what is ethical. That is a matter for individuals and for societies. But science can clarify the questions being asked, and can clear up obfuscating misunderstandings. This usually amounts to the useful: “you cannot have it both ways” style of arguing.
Granny Weatherwax (auth: Terry Pratchett): Trouble is, just because things are obvious doesn’t mean they’re true.
Albert Einstein: Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.
Carl Sagan: You can’t convince a believer of anything; for their belief is not based on evidence, it’s based on a deep seated need to believe.
Charles Darwin: Ignorance more frequently begets confidence than does knowledge.
Richard Feynman: It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong.
Stephen Jay Gould: The invalid assumption that correlation implies cause is probably among the two or three most serious and common errors of human reasoning.
Menu of separately published pages.
Testing Autotrace - a demonstration of a special case in autotrace.
Statspack Examples - a list of pointers to Web articles about interpreting statspack.
Statspack Distractions - an example of the “obvious” problem not being the right problem.
Join Ordering - a discussion about tuning a particular class of SQL statement
Comments about Comments
Just a few notes about contributing. Please check the details about tags and formatting at the end. WordPress does some odd things with comment text.
Delayed comments
The blog is protected by Akismet, which tries to identify blog-spam. As a consequence, it is possible that a comment you post will not appear because it has been marked as ‘possible spam’. This is particularly likely to happen if you include a few URLs (such as Metalink, other blogs etc.) in the comment. If you post a comment that doesn’t appear within a few minutes, send me an email, and I will ‘despam’ it as soon as I can.
Code Demonstrations
It’s becoming quite common to see code samples being used to demonstrate a point. The commonest presentation seems to be to run from an SQL*Plus session with echo on so that the SQL and the response to the SQL alternate.
I actually prefer to see the SQL as a continuous script - its easier to view, and I like to read through the script and predict the results before seeing them; so my approach is simply to paste the code, then run the script with echo off and paste the results. Do take a look at the comment further down about spaces disappearing and how to deal with that problem.
Cross-chat
If you reply to someone else’s comment, it’s a good idea to start your comment with their name in case another unrelated comment arrives between the original and your reply. It is also quite helpful to quote a line or two from the original if you are just commenting on a specific detail.
Losing text:
It’s been really difficult writing the following three sections on text appearance, because the visual editor code keeps mangling my carefully constructed examples as I switch between edit modes. If you see odd empty spaces in the instructions, please drop me an email to let me know it’s gone wrong again.
Various problems appear because many of the normal html tags are removed by the visual processor when you use them in comments. Most significantly, the <pre></pre> tags do not work, although the <code></code> do persist - but they still lose whitespace.
“Less than” in code:
If you start writing SQL in comments, be careful about < symbols. Anything from one of these to the next > will disappear when you publish. You need to replace the symbol with the text < (including the semi-colon).
Spaces in Edits:
When you create a comment (in the theme I have used), all white-space is eliminated, and there doesn’t seem to be an easy way to stop this happening. However, I have found that if I do a ‘global find and replace’ to change spaces to the text (including the semi-colon) then you get whitespace where you need it.
Of course, it’s a nuisance to do, and even more fiddly if you have tab marks in your text, but if you want to make a point about code or output, it’s much more likely to be read by other people if you’ve managed to get the text alignment working.
Emphasis in Comments:
There are two possibilities that I’ve found to work so far:
- em gives you italic script, as does the single letter i
- strong gives you bold, as does the single letter b
- h1, h2, h3, h4, h5 give you options for headings - h4 is a good size
In these cases you have to use the html tag syntax, for example: <em> to start the highlight, and </em> to end it.
Accidents:
There doesn’t seem to be a preview option available (with this theme, at least), so if you do have an accident when entering a comment, remember that I can edit or delete your comment. So if you have to “finish” off a comment that you published by accident, you can either type the whole thing in again - and I’ll delete the earlier copy; or you can create an ending section - and I’ll cut and paste the two bits together for you..
