

Enrollment for Stanford's online DB class now open - roger_lee
http://www.db-class.org/course/auth/welcome

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pbh
To answer a few of the database questions that keep popping up in this thread:

1\. Is it worth understanding relational algebra? Yes. Definitely. It's not
that hard, there's more or less a one-to-one mapping of relational algebra to
SQL. Relational algebra is both a useful mathematical tool and indispensable
when trying to understand query optimization. Relational algebra is also
necessary to be able to read pretty much any of the database literature, if
that's one of your goals. (Just be thankful you don't have to learn Relational
Calculus or Datalog.)

2\. Is it worth learning XML features like XML DTDs, XPath, XML Schema, and
XQuery? Yes, definitely. I don't like XML, but there are tons of places where
you can use XPath. (The most interesting thing about XQuery is probably how
similar it is to SQL, though.)

3\. Is it worth learning about SQL triggers? Probably. Ultimately, the web
development world is split between people for whom separation of concerns
means doing more in the database, and those for whom separation of concerns
means doing less in the database. If you think doing validation and
transactions in the database is sensible, triggers are also a sensible thing
to learn about. However, people like DHH disagree and want validation in your
app server with a dumber backend.

4\. Is this vocational training? Well, this is the first in a three class
sequence at Stanford. This class is mostly about schema and query languages,
so in some sense, it's the most useful to practitioners (or at least, non-DBA
practitioners). The second class is about systems and implementation (on-disk
layout, indexing structures, query optimization). In the third class, students
either learn about distributed databases or actually build their own from
scratch. However, schema and query languages have enough theory behind them,
and enough generality, that I wouldn't consider it any more vocational
training than a class on compilers.

~~~
dzlobin
Do you happen to know if the other two classes in this series will be
available online as well?

~~~
pbh
Unknown.

However, the three classes are intended to match up with Database Systems: The
Complete Book (which, in the interests of full disclosure, is written partly
by my former advisor). If you want to learn the material from the second
class, I would just read the book. I've actually read the book cover to cover,
and I think it's one of the best textbooks for that purpose. There are tons of
examples everywhere, it's pretty talkative, and there is very little
pretension (insert Russell/Norvig complaint here). On the other hand, some
portion of the Internet seems to take the opposite view (e.g., some people
just view the talkativeness as repetition).

~~~
dzlobin
Fantastic, thanks for the info!

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skymt
As are the AI and ML classes.

<http://www.ai-class.com/> <http://www.ml-class.org/>

~~~
meese_
When do these officially start?

~~~
Nic0
10 october for the ai-class, probably around the same date for the others
classes.

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amirmc
Just as a reminder for folks, there's a spreadsheet of HN readers who are
taking part in the classes at <http://bit.ly/pLCRzg>

There are 120+ HNers on there so you might find folks nearby you'd like to get
in touch with.

Edit: Obviously, if you're doing any of the courses feel free to add your
details too

~~~
mkopinsky
I have always known that the "right" way of presenting dates is as "2011-09-25
23:52" for the sake of sorting. This spreadsheet has prompted me to think that
the "right" way of presenting locations is actually "USA, NY, New York[,
Streetname 1234]" for the same reason.

~~~
amirmc
I'm inclined to agree. It was unordered before but looks like someone sorted
it by location.

~~~
mkopinsky
The problem with the new sorting is that it easily shows who's in the same
city, but doesn't show who's in the same state. Yonkers, NY is not far from
NYC, but is very far alphabetically.

~~~
amirmc
I just realised that my previous post may have been a bit ambiguous. Just for
completeness, what I meant was that the spreadsheet was previously unsorted
(people would add their details at the bottom) and that someone came along and
sorted it by location (presumably to make it easier for people to find each
other). However, the sorting doesn't really solve the problem, as you
correctly describe.

I made a new column and started adding details in reverse (e.g USA, NY).
Admittedly I got a little bored so I didn't do everyone. Re-sorting on that
column (if it's ever completed) would solve your problem.

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jules
I watched the first 6 videos and I have to say it is a bit boring. It feels
more like vocational education on using man made contraptions than a
university course. I was hoping for a course on how databases work: indexing
structures (B-trees, COLAs), query optimizers, transactions, column vs row
storage, etc.

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crag
I love the course. But I'll admit, the XML section; I was fighting to stay
awake.

And relational algebra? Com'on...

~~~
judofyr
I haven't signed up for the DB class so I'm wondering: what's up with the
relational algebra?

~~~
crag
There's a section on it. My first reaction was "Good god.. NO!!!! Not
relational algebra!".

After a cup of coffee I made through the 2 videos.

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rmnoon
I took this class from Prof. Widom at Stanford. It was...meh.

Are SQL triggers still relevant? How much relational algebra do you really
need to know? I think I've used this stuff maybe once since then.

~~~
autarch
To answer your questions ...

1\. Yes, they are. They're very useful for certain things. For example, want
to update your fulltext index in Postgres after certain table cells change or
when new rows are inserted? You'll need to use a trigger.

2\. Knowing more rather than less is probably a good thing. Understanding the
underlying model of relational data will help you build SQL databases that
make sense given the data you're working with.

Of course, you won't use SQL in every project or job, but it's awfully useful.
Ignore the hype that NoSQL is the wave of the future. It may be _a_ wave of
the future but so is SQL.

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LuxuryMode
I don't get how to read the answer choices for this question:

<!DOCTYPE A [ <!ELEMENT A (B+, C)> <!ELEMENT B (#PCDATA)> <!ELEMENT C (B?, D)>
<!ELEMENT D (#PCDATA)> ]> Which of the following sequences of opening and
closing tags matches this DTD? Note: In actual XML, opening and closing tags
would be enclosed in angle brackets, and some elements might have text
subelements. This quiz focuses on the element sequencing and interleaving
specified by the DTD.

What does this mean for example? A B /B B /B C B /B D /D D /D /C /A

~~~
mkopinsky
<A> <B> </B> <B> </B> etc.

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lambada
Any idea why the AI class website looks so different to the ML and DB classes?
It doesn't even use the same TLD, let alone have the same style.

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grinnbearit
It looks like the ML class is up too <http://ml-class.org>

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eldina
Is it clear whether these open courses will be repeated in the future or if
they are mainly tests before starting to charge ? It is wonderful that they
are freely available but can it really be a permanent thing and what does
Stanford gain ?

~~~
KC8ZKF
Stanford is a corporate trust charged with educating the public. These classes
are in service to that. Isn't that enough?

~~~
eldina
It is more than enough. I am just surprised that this is doable at
universities where "proper" students pay serious money for getting a degree.

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nphase
Can I follow the advanced track at my own pace without being forced to
participation? The advanced track of all of these classes seem to require
participation, which I can't guarantee on their timeline right now.. (yay
startup life!)

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smackfu
The XML quiz is quite annoying since it requires checking each answer against
the DTD, but the DTD + answers are too big to fit on one screen even on a big
monitor, so you keep needing to scroll back and forth.

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yequalsx
I've tried searching for a list of Stanford's online open enrollment courses
and haven't found anything. Is there a website that details their course
offerings and a list of planned courses?

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pbreit
Love that you can speed up the videos to 1.5x (in the Flash version).

Don't love the Flash.

Like that an HTML5 alternative is offered for iPads, etc.

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beaumartinez
As I got told in the email as I enrolled–"The class will run from October 10
to December 12".

~~~
telemachos
Yup, but also note this (from the home page, once you've logged in to the
class):

 _The class has not yet officially started, but in this pre-launch period, you
can begin looking at the first week of content so that you can see what's
coming and get a head start._

Since there's already quite a lot of video uploaded (and three
quizzes/assignments), I'm happy to get started early.

~~~
beaumartinez
Hm, I meant it more to indicate when it ended ;)—also, the option to view the
lessons at 1.2x speed is a godsend.

~~~
mkopinsky
Yes, I am a huge fan of 1.2x speed. I find it easier to concentrate when the
information is coming at me a little bit faster.

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fallenlad
Enrolled in DB class, wish i could join AI too.

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burrokeet
cool class even though I failed my EE qual session with Prof Widom :)

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Kaedon
Awesome, thank you for posting this.

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rosariom
Thanks man this is an ultra cool subject!

