Honest

I may say more about this eventually post by Brian T. Murphy but I love how honest it is; kinda speaks for itself.

Serving With Code

As I thought about practicing my faith I wondered what my place was. We make good money and give generously. But is that all I'm supposed to be doing, or should I quit it all, cash out the equity in our house, move our family to a "poor neighborhood" and serve like Shane and The Simple Way. Sometimes I would lean towards the later, but then that doesn't seem the least bit feasible and would I really be using my gifts and abilities?

I have a friend who is the pastor of Redeemer Presbyterian in Indianapolis. Our family has been helping financially with a small and wonderfully unique congregation that he and Redeemer have helped to get off the ground called The New Deal. About once a year we get to see Jason and his family in Indy. We did again in August. While visiting, he introduced us to Tim Streett who founded Jireh Sports. Jireh is an inspiring organization dedicated to "meet the spiritual, physical, mental and emotional needs of urban youth...through significant relationships with mentoring adults developed around unique sports, recreation, and educational opportunities."

The reason I mention Jireh is because it got me thinking. I'm not a guy that could start a gym, but could I start a program to mentor underprivileged children about computers. Is it possible to have an aftershool program that teaches kids how to use computers, how to take them apart and put them together again, to learn about logic and math, to learn how to program them? I suppose the curriculum would have to have healthy doses of video games also ;) Perhaps more importantly would kids be interested in that, and would it make a difference in their lives? Perhaps this will be another idea in the list of many unimplemented ideas? But let's try anyhow, or at least act like we're trying....

I always start with naming a project. In this case, because I have another idea for how to start developing a curriculum that's gonna need a website. So audience; all five of you (thanks Mom)... What should I name such an endeavor? Here are a few ideas that I'm considering:

• codeducate (or codeducator)


• bit professor


• code kids (I couldn't bring myself to use a 'k' for kode ;)


• bits for kids (as in "silly rabbit bits are for kids")

What do you think?

Books that Change You

A couple of weeks ago I finished reading "Irresistible Revolution" by Shane Claiborne. It is without a doubt the most challenging and mind changing book that I've read in a long time. Shane's practice of Christianity is remarkable. I've often wondered what it would look like to be in a Christian community that looks like the church in Acts 2:42-47 today. So much is different about the world now than 2000 years ago that it seems impossible (for example transportation has made it possible for people to live a long ways from their church, job, family, and friends). However, thanks to Shane and his fellow "revolutionaries" at The Simple Way I now know.

I first read about the concept of orthopraxy in the work of Brian McLaren. Orthopraxy means "right practice" whereas the more familiar term orthodoxy means "right thinking". Many churches that I've attended focus almost exclusively on "right thinking"; on understanding Jesus and our relationship to him, but too often in the life of a Christian it stops there. The Christian faith is an active one, it must be practiced in sacrificial love and acts of service and we should never be satisfied with believing the "right thing". I'm not saying that orthodoxy is unimportant. In fact it is often foundational to orthopraxy. But not always... Recently I heard a story of the faith journey of a woman (it was wonderful to hear) and God moved in her life and she started "practicing" Christianity before she even understood really what it meant to be a Christian. The point is simple "right thinking" should never innoculate us from "right practice."

I had planned on including lots of great quotes from Shane's book like one from Mother Teresa: "In this life we cannot do great things. We can only do small things with great love." But there's too many. When I read books I dog-ear the top corner of the page to mark where I am, and I dog-ear the bottom corner of the page to mark things that I want to remember. My copy of the book is nearly twice as thick because of my dog-earring. So, you'll have to read it yourself to get the good stuff. If you're a Christian be ready for a wild ride. If you're not, read it anyway to see a Christianity unlike ANYTHING you've seen on TV, or pushed on you by your "hypocrite neighbor." I make this promise. If you don't find anything of value in the book. I'll give you your money back (actually Shane makes that promise in the book... actually he's giving away all of the proceeds anyhow)

Reading banned books...

As part of Banned Books Week (http://www.ala.org/ala/oif/bannedbooksweek/bannedbooksweek.htm) I’ve decided to read (probably not all all in the week ;)

• Slaughterhouse 5 by Kurt Vonnegut (http://www.amazon.com/gp/product/0440180295)

• A Wrinkle in Time by Madeleine L’Engle (http://www.amazon.com/gp/product/0440498058)

• I Know Why the Caged Bird Sings by Maya Angelou (http://www.amazon.com/gp/product/0553279378)

I’ll let you know how it goes!

See more progress on: read a banned book for Banned Book Week (September 23–30)

Prediction #1: MySpace

My recent ranting about Amazon Unbox has inspired me. I jumped into the Amazon Unbox experiment with the best intentions genuinely hoping that they'd have a better offering than what I was getting with iTunes Music Store, but I left predicting that it wouldn't work in the current marketplace. I hadn't read any opinion about it but it appears that Unbox may be getting a cold shoulder. Especially in light of Apples recent announcments of improvements to iTunes Music Store and the upcoming iTV.

So since I'm feeling particularly prophetic I've decided that I'm going to start making public predictions and cataloging them here. I give you prediction #1.

MySpace will fail within the next two years; just like Friendster and Orkut, etc.

I was reading this article by Dare Obasanjo and it all came together for me. If they only focused inward on what they've seemed to capture mindshare with (which I think is crappy home pages that help teenagers find dates, that and band home pages) I still think they would fail when teenagers get bored of the site or when social networking gets integrated into the next Motorola phone (hey maybe that's a prediction too ;). But then if they start trying to build a better Flickr, and a better YouTube and a better mousetrap, they're sure to do a mediocre job at everything. I like what David Heinemeier Hansson says "Don't build a half-assed product... Build half the product." So there! May you rest in peace MySpace.

MySQL "group-wise limiting"

Time to really geek out. I've run into this class of problem a bunch of times over the years and I've never seen an answer that I like.

I've got a query that I'm using GROUP BY for. Is is possible to limit the rows per group.

Every SQL dialect that I've seen makes it possible to limit the rows in a results set. Usually something like:

mysql> select * from sometable limit 10;

and you'll get only the first ten rows. However, when you introduce grouping it all falls apart. Consider this schema representing (denormalized) grades for different students from two classes:

create temporary table groupwise_select(
id int not null primary key auto_increment,
class_id int not null,
name varchar(255) not null,
grade float not null);
insert into groupwise_select(class_id, name, grade) values(1, 'Andy', 100.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Andy', 98.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Andy', 99.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Andy', 97.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Bob', 97.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Bob', 98.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Bob', 65.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Henry', 32.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Henry', 33.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Henry', 34.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Henry', 35.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Henry', 100.0);
insert into groupwise_select(class_id, name, grade) values(1, 'Amelia', 73.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Valerie', 100.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Valerie', 100.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Valerie', 100.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Valerie', 100.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Valerie', 100.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Hans', 13.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Hans', 14.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Hans', 15.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Hans', 16.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Oscar', 99.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Oscar', 99.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Oscar', 99.0);
insert into groupwise_select(class_id, name, grade) values(2, 'Oscar', 104.0);

Your assignment is to return the two best students (highest average) from each class. OK, great. Lets start with a simple grouping query to return the average for each student

mysql> select class_id, name, avg(grade) as average from groupwise_select group by name, class_id order by class_id, average desc;
+----------+---------+-----------------+
| class_id | name    | average         |
+----------+---------+-----------------+
|        1 | Andy    |            98.5 |
|        1 | Bob     | 86.666666666667 |
|        1 | Amelia  |              73 |
|        1 | Henry   |            46.8 |
|        2 | Oscar   |          100.25 |
|        2 | Valerie |             100 |
|        2 | Hans    |            14.5 |
+----------+---------+-----------------+
7 rows in set (0.01 sec)

Good we now know that the four students we need to return as the answer are Andy (98.5), Bob(86.7), Oscar(100.25), and Valerie(100). This should be easy let's just use a LIMIT

mysql> select class_id, name, avg(grade) from groupwise_select group by name, class_id LIMIT 2;
+----------+------+-----------------+
| class_id | name | average         |
+----------+------+-----------------+
|        1 | Andy |            98.5 |
|        1 | Bob  | 86.666666666667 |
+----------+------+-----------------+
2 rows in set (0.00 sec)

Hmmm... That only returned the first two rows from our previous query. Yep, that's because the LIMIT is applied as the last thing the query does. Now you'll probably bang your head against the wall trying all different variations of GROUP BY, ORDER BY, and LIMIT at this point and ultimately you'll end up doing the LIMITing in application code instead of SQL concluding that it's just not possible.

However, there is a solution! It uses MySQL's user defined variables and sub-selects. Let's jump to the answer:

mysql> set @idx=0; set @cur_class=0;
mysql> SELECT class_id, name, average FROM (
SELECT r.class_id, r.name, r.grade,
IF(@cur_class != r.class_id, @idx:=1, @idx:=@idx+1) AS row_index,
IF(@cur_class != r.class_id, @cur_class:=r.class_id, 0) AS discard
FROM (SELECT class_id, name, avg(grade) AS average FROM
groupwise_select GROUP BY name, class_id
ORDER BY class_id, average DESC) AS r
HAVING row_index <= 2) AS r2;

+----------+---------+------------------+
| class_id | name    | average          |
+----------+---------+------------------+
|        1 | Andy    |             98.5 |
|        1 | Bob     | 86.6666666666667 |
|        2 | Oscar   |           100.25 |
|        2 | Valerie |              100 |
+----------+---------+------------------+
4 rows in set (0.01 sec)

Awesome! So how does that work. There are probably a few key insights here:

1. sub-selects must evaluate in their entirety before the outer-select (in this case our query returns the averages for ALL of the students sorted first by class_id and then by average)


2. The true and false expression parts of the IF() function can be used to set user-defined variables


3. IF() function expressions included in a SELECT statement are evaluated left to right


4. You can't use a WHERE clause on a computed column (like row_index) but you can include it in the HAVING clause (I don't presume to really understand that)

So given those insights we first retrieve ALL of the GROUPed averages for the students order by class_id and then average, second we number the results for each class, and last we trim out the rows that have a row number less than or equal to our target (2 students per class). Voilla! Group-wise limiting.

Cringley Article

Robert X. Cringley wrote an article about Apple's pending announcement In which he makes some points similar to mine

"This is key, because what's been missing throughout this conversion to Internet television has been a way to incorporate our user device of choice -- the TV. People don't really want to watch movies on their computer screens. They'll do it, some of them, but most people won't, so for the Internet and downloadable video market to explode the way it is supposed to do, we need an easy way to get the movies out of our computers and onto our TV screens."

The question remains about Amazon UnBox... How will they get the content to the TV. If it's through a player then they chose the wrong set of devices.

Amazon Unbox

Over the last two or three years I've basically stopped buying CDs opting instead to buy music digitally (except for artists on really small labels). And within the last few months, since I got my video iPod, I've started to buy video content digitally too (Shiree and I are HOOKED on Prison Break).

Because I have a Mac and iPod I've been doing all of my purchasing through the iTunes Music Store, and while I have my beefs with them (DRM prevents playing on non Apple software, there's no "wishlist", navigation is poor, etc.) it's been a great experience and I'm hooked. That said, when Amazon announced Amazon Unbox I was intrigued and wanted to try it. I read a little bit and noted that buying a video gets you "DVD-quality video to watch on your PC or TV, and a video file optimized for compatible portable video players". I just assumed that would work on my Mac/iPod setup. Nope! Not only does Amazon Unbox not work for the iPod, it doesn't work on a Mac either. The iPod bit is understandable. I'm sure the media companies aren't licensing the content without DRM and Apple's DRM for the iPod is it's special sauce that it won't open up to competitors. I suppose it's even reasonable to not support the Mac since it's only 10% marketshare or somesuch.

However, I don't see a non-iPod strategy working out. As of now, people are not going to watch video content on their PC and you're right to point out that people are not watching video content on their iPod either. BUT, they will dump the video content onto a player and then plug it into their home entertainment system (for example I use a n RCA/video cable). So, as of now, Amazon is trying to compete in 13% of the player market and maybe not even that much because they support a pretty limited set of players.

Joel on Software

It's been a while since I've written anything and so it's strange that I would dip back into the water on a topic like this but within the span of a week I've decided that I'm over Joel Spolsky.

First I think he's starting to recycle content (like his latest Finding Great Developers). If it's NOT recycled it feels like it. So at a minimum he's no longer saying things that I don't already know. Then last week there was the whole Language Wars rant (and the answer from DHH). I don't really even know what to say about that except "did someone pay him to say that stuff?"

So thanks for the insights over the past 6 years, but Joel, I'm afraid that you've Jumped the Shark.