October 6, 2011 at 12:48 am
Good questions Tom - only got 2 out of 3 - still learnt (again) today
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October 6, 2011 at 3:46 am
L' Eomot Inversé (10/5/2011)
I wish I knew some more familiar terminology. I suppose for "prime attribute" one can use "key attribute" (although the SQL influence on terminology means that a key attribute may allow nulls that case is covered bu other options) but "fixed" is just normal English (or American) and I'm not aware of any other term at all for "elementary key".If you can suggest any better terms, I'll be glad to hear them - and will maybe use them in an article soon.
Tom
I think using the word "column" instead of "attribute" would be a start.
I've had a look at Sgr Zaniolo's paper and my eyes glazed over when I tried to understand the definitions of "functional dependency" and "elementary key". The fact that there is no other term for the latter suggests that we're deep into the realm of arcane theory. Not that there's anything wrong with that - I'm just surprised at your surprise that more people don't understand it fully enough to be able to answer the question.
I certainly look forward to your article - especially if it goes any way towards demystifying all this theory!
John
October 6, 2011 at 4:24 am
mtassin (10/5/2011)
Another note.. go to http://www.google.com and type in EKNF and BCNF. I know which one you'll get an immediate hit on.
I was pretty sure that was nonsense, but I decided to check anyway. I went to google (https://encrypted.google.com/webhp?hl=gd - I care about security so don't use the insecure http://www.google.com and of course want to work in my own language where possible, and google obligingly allows me to) and tried typing in eknf. Instant response (small fraction of a second) with about 45000 hits. That seems to me to confirm that what I thought was nonsense is indeed nonsense.
Tom
October 6, 2011 at 5:40 am
Tough question, I really had to think through this one.
http://brittcluff.blogspot.com/
October 6, 2011 at 6:35 am
L' Eomot Inversé (10/6/2011)
mtassin (10/5/2011)
Another note.. go to http://www.google.com and type in EKNF and BCNF. I know which one you'll get an immediate hit on.I was pretty sure that was nonsense, but I decided to check anyway. I went to google (https://encrypted.google.com/webhp?hl=gd - I care about security so don't use the insecure http://www.google.com and of course want to work in my own language where possible, and google obligingly allows me to) and tried typing in eknf. Instant response (small fraction of a second) with about 45000 hits. That seems to me to confirm that what I thought was nonsense is indeed nonsense.
It is not nonsense. When I look them up on google.com in English, which is what was posted, I get some hits for EKNF but almost all of them are acronym lists with no actual information available. (A notable exception is Mr. Celko's book which is now probably going to be added to my stack of books I never seem to have time to read.) However, I get tons of actual information on BCNF when googling it. I make no comment on using the encrypted Google web page you cite in French, because I don't speak French and am apparently not so security conscious as to avoid the vanilla Google page.
October 6, 2011 at 7:00 am
Can I blame it on the spelling mistakes? 😉
October 6, 2011 at 7:50 am
L' Eomot Inversé (10/6/2011)
mtassin (10/5/2011)
Another note.. go to http://www.google.com and type in EKNF and BCNF. I know which one you'll get an immediate hit on.I was pretty sure that was nonsense, but I decided to check anyway. I went to google (https://encrypted.google.com/webhp?hl=gd - I care about security so don't use the insecure http://www.google.com and of course want to work in my own language where possible, and google obligingly allows me to) and tried typing in eknf. Instant response (small fraction of a second) with about 45000 hits. That seems to me to confirm that what I thought was nonsense is indeed nonsense.
Ok so Google has decided that if I type in EKNF that I mean EKSF that should say something there as well.
October 6, 2011 at 8:29 am
Thanks for the question Tom.
Jason...AKA CirqueDeSQLeil
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October 6, 2011 at 1:39 pm
mtassin (10/5/2011)
I think a big part of this is the flavor of Normalization Kool-aid we're using.For instance, this paper that's referenced isn't necessarily Normalization Form mainstream.
I find it amusing to see a claim that a seminal paper by the man who id now director of the UCLA Web Information System Lanboratory and holder of UCLA's N. E. Friedmann Chair in Knowledge Science, an associate editor of VLDB Journal, who has been program chair or general chair of VLDB (more than once), SIGMOD CMD, NACLo, NID, EDBT, and chaired HotSWUp in April this year should be dismissed as not necessarily mainstream. Who cares what the commercial mainstream is, when it's people like Zaniolo who aid us in understanding where we are at? If Codd had been dismissed as "not mainstream" (and he certainly wasn't mainstream until at least 1980) we would have no relational database systems at all today.
Of course it depends partly on what you think normalisation is about. There are two schools:
One school believes that normalisation should be an attempt to prevent bugs - to ensure that the schema, through its constraints, enforces as far as possible the business rules that apply to the data, so that careless programming can't cause the data to reach a state in conflict with the business rules. That's my school.
Another school believes that normalisation is about decomposing relations as far as is possible without losing information in the data (losing constraints that represent business rules is perfectly acceptable, since according to this school that information doesn't count as information). That's not my school. It is Chris Date's school, as is made claim by his comments on Fagin's 6NF (aka DKNF) (with which I happen to agree) when he wanted to call his own new form "6NF" (he succeeded, we all call Date's normal form 6NF now) so your referencing his textbook as if he were an eminent authority with no axe to grind pulls no weight at all; should I reference Carlo Zaniolo's equally weighty textbook? I think not, such references are pointless.
A third way of looking at it is to believe that whatever is in popular textbooks, regardless of the scientific literature, is all of normalisation and representation theory. I can't justify attaching the title "school" to followers of that approach, so I can't ask if it's your school.
Tom
October 6, 2011 at 1:44 pm
Ernie Schlangen (10/6/2011)
I make no comment on using the encrypted Google web page you cite in French, because I don't speak French and am apparently not so security conscious as to avoid the vanilla Google page.
In French??? Where on earth did that come from?
Did I type "fr" instead of "gd"? Actually, I'm pretty sure I didn't because I think I just copied (copy and paste, just mouse clicks, no typing) my home page address!
Tom
October 6, 2011 at 3:01 pm
L' Eomot Inversé (10/6/2011)
Ernie Schlangen (10/6/2011)
I make no comment on using the encrypted Google web page you cite in French, because I don't speak French and am apparently not so security conscious as to avoid the vanilla Google page.In French??? Where on earth did that come from?
Did I type "fr" instead of "gd"? Actually, I'm pretty sure I didn't because I think I just copied (copy and paste, just mouse clicks, no typing) my home page address!
Too bad we can't all be as intelligent, learned and multilingual as we'd like. Considering that your current nom de post and signature lines certainly look to be in French, I'd guess that's where on earth from whence Ernie's confusion arose.
October 6, 2011 at 3:28 pm
It looks like the encrypted Google page was in Gaelic.
October 6, 2011 at 3:37 pm
john.arnott (10/6/2011)
L' Eomot Inversé (10/6/2011)
Ernie Schlangen (10/6/2011)
I make no comment on using the encrypted Google web page you cite in French, because I don't speak French and am apparently not so security conscious as to avoid the vanilla Google page.In French??? Where on earth did that come from?
Did I type "fr" instead of "gd"? Actually, I'm pretty sure I didn't because I think I just copied (copy and paste, just mouse clicks, no typing) my home page address!
Too bad we can't all be as intelligent, learned and multilingual as we'd like. Considering that your current nom de post and signature lines certainly look to be in French, I'd guess that's where on earth from whence Ernie's confusion arose.
That is indeed the case. I didn't look at the link you posted since you had already stated it was in something other than English. Even if I had, I know even less Scottish Gaelic (i.e. none and had to lookup gd to find out what language it referred to) than I do French (almost none)! All I was really trying to say was that the results I saw came from the http://www.google.com page in English and that my comment was based solely on this, which is not necessarily the same results that you were looking at (language aside).
October 6, 2011 at 5:34 pm
Ernie Schlangen (10/6/2011)
I didn't look at the link you posted since you had already stated it was in something other than English. Even if I had, I know even less Scottish Gaelic (i.e. none and had to lookup gd to find out what language it referred to) than I do French (almost none)! All I was really trying to say was that the results I saw came from the http://www.google.com page in English and that my comment was based solely on this, which is not necessarily the same results that you were looking at (language aside).
OK, that's fair enough, you guessed the language from my current SQLSC nickname - but surely you know the layout of Google's front page well enough that it doesn't really matter what language "advanced search" and "I guess I'm lucky" (or whatever the English versions are) and so on are in, particularly since typing eknf and hitting enter is all you would need to do. Anyway, it seems unlikely that a search at encrypted.google.com should produce results different from the same search at http://www.google.com, and even less likely that my choice of google interface language should mean I get more results than someone who chooses English (I am pretty sure that there are no results in Scots Gaelic for eknf), and it was the claim that such a strange discrepancy did indeed exist that I was objecting to.
Tom
October 6, 2011 at 5:51 pm
L' Eomot Inversé (10/5/2011)
I find it quite frightening that so few people know enough about normalisation to get this one right.
I feel much less frightened now: 22% out of 700 is a lot better than 2% out of 200.
Tom
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