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This year I will be posting directly to the blog, rather than sending out e-mails to everyone like I've done in previous years. The easiest way to get notified of updates is via a news aggregator . A news aggregator is similar to your Web browser, but with the added feature that it lets you know when new posts have appeared. This saves you the chore of having to check the Websites you are interested in "by hand." In other words, it's so....
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This year I will be posting directly to the blog, rather than sending out e-mails to everyone like I've done in previous years. The easiest way to get notified of updates is via a news aggregator . A news aggregator is similar to your Web browser, but with the added feature that it lets you know when new posts have appeared. This saves you the chore of having to check the Websites you are interested in "by hand." In other words, it's so....
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This year I will be posting directly to the blog, rather than sending out e-mails to everyone like I've done in previous years. The easiest way to get notified of updates is via a news aggregator . A news aggregator is similar to your Web browser, but with the added feature that it lets you know when new posts have appeared. This saves you the chore of having to check the Websites you are interested in "by hand." In other words, it's so....
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Do you speak test? In that case: Hello web application: public class WebIntegrationTest extends net.sourceforge.jwebunit.WebTestCase { public void testIndex() { beginAt("/index.html"); assertTextPresent("Hello world"); } private org.mortbay.jetty.Server server; protected void setUp() throws Exception { server = new org.mortbay.jetty.Server(0); server.addHandler( new org.mortbay.jetty.webapp.WebAppContext("src/main/webapp", "/my-context")); ..
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On my sixth trip to the South Pole, I will try to publish at least one drawing or photo each day, possibly including some text.
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On my sixth trip to the South Pole, I will try to publish at least one drawing or photo each day, possibly including some text.
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On my sixth trip to the South Pole, I will try to publish at least one drawing or photo each day, possibly including some text.
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The security people at my were suggesting that we needed to create an encryption service, to securely store passwords so that even rogue DBAs could not get at them. The idea is that no matter how good your access is to the database, you shouldn’t be able to decrypt the passwords unless you have the secret key. In a solution like this, the key is generally stored offline with the application and loaded into memory sometime during startup.
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Now, this one has been on my TODO list for a while : Trip to LatinoWare and OpenBeach 2005, and the Nivea Sun sailing race in Brazil
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The `SUM(col)` of zero rows should zero, but is instead `NULL`
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www.databasesandlife.com
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19 years ago
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eng
I must admit I get bitten by this regularly. The SQL standard states that aggregate functions should return NULL if no rows are processed (with the exception of COUNT). This means that computing the SUM of zero rows returns NULL as opposed to 0. This goes against mathematical intuition. If I have zero USB sticks, how much data can I store on my USB sticks? The answer is 0 bytes, but modelling USB sticks in a database would return “und..
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The old expression “Mac users usually swear by their computers…..Windows users typically swear at their computers” got to me last week when my instructor computer’s Windows desktop and applications froze 3 times at the beginning of class. As a result, my Terminal Services connection (that I use to record daily quiz marks) was destroyed each time. So I brought an old iMac G3 with OS X Tiger into my classroom this week and put it on a switc..
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The old expression “Mac users usually swear by their computers…..Windows users typically swear at their computers” got to me last week when my instructor computer’s Windows desktop and applications froze 3 times at the beginning of class. As a result, my Terminal Services connection (that I use to record daily quiz marks) was destroyed each time. So I brought an old iMac G3 with OS X Tiger into my classroom this week and put it on a switc..
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In my last post, I wrote about four integration scenarios using databases: Reference data, Consolidated view, Subscription and Publishing. Of these, the Consolidated View scenario requires the most interaction between the server and the client roles. This post will examine how to make the pieces fit together. Consolidated view joins the data of multiple clients into a consolidated view. This makes you able to create administrative applicati..
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In my last post on using the database for integration, I argued that the best metaphor for creating systems that are interconnected is that of One-Large Database. Carl-Henrik asked some very relevant questions about this, which I will interpret (for now) mainly as “how do you avoid drowning in complexity”. This post will address the issue of maintainability, especially when things grow to be large. The On Large Database metaphor is mostly u..
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I got the following addition on my Dell XPS LED code from David Pritchard. The new version of the code has a “-touchpad” argument. Specify “-touchpad 1” to turn the XPS 2 touchpad light on, “-touchpad 0” to turn it off. Here is the updated source code and executable. The executable should work without Cygwin now. (Note to self: Use “-mno-cygwin” gcc option to strip out the dependency)
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I started to get errors when using gmail. Gmail is normally very reliable. I would enter the URL in Firefox, the white background with “Loading…” top-left would appear, then a little later “This appears to be taking longer than normal” would appear, and that was it. It turned out, I only got the errors when using a T-Mobile UMTS card (in Austria). This has an option to “compress images” which is on by default. This means that JPEGs look..
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The Supreme Administrative Court has ruled that Lord Mayor Jussi Pajunen was disqualified to decide the fate of the historic Helsinki-Malmi airport . Helsingin Sanomat reports : Pajunen participated in the preparation of Helsinki’s general land use plan 2002 in the Helsinki city council. At the same time he was also the president of the Malmin Nova company. The company had business in the Malmi shopping center. In addition the comp..
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Honking Cars in Egypt, especially Cairo honk all the time. Day and night. If we woke up at 4 am in the hotel room, there would be cars honking outside. The honk to wake up pedestrians or other cars, taxis honk to attract the attention of potential customers, and often, it seems like they honk just for the fun of it. Security There’s a ton of policemen in Cairo, easily recognizable by their white uniforms.
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After a rather unsuccessful day, we decided to have a more aggressive program the last day in Cairo. We started out early with a subway trip to Coptic Cairo. It seems that very few tourists are using the subways, which is a pity because it is a pretty good system. If they only could have any information in English. We had to trust the ticket guy who said it was LE 2 for both of us.
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We had a late start on Wednesday. We are going to take the train to Alexandria, and we want to make sure that we get the tickets, so we start with a trip to Ramsees railway station. I had expected the trains (which seem nice from the guidebook) to be much used by tourists, but as it turned out, all the information was in Arabic, with the platform numbers, and the word “platform” as the only thing in English.
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In Cairo, we have noticed a recurring theme. Many places that are visited a lot by westerners are sectioned off from the rest of the city. When Egypt was a British colony, the colonialism was expressed by importing British culture into Egypt. With modern colonialism, a section of the western world is placed wholesale as a small colony inside the city. After a rather tiresome day, we didn’t feel like we had the energy to go egyptian style ag..
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Letters from Cairo III: Abou el-Sid, traffic and ancient artifacts
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jhannes.github.io
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19 years ago
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eng
Abou el-Sid is located in Zamalek along the Sharia 26th of July. The doorman for the hotel hailed a cab for us (and got a bit of baksheesh for that, I don’t know if that was right), and negotiated an overpriced fee. :-) The traffic is seeming more and more what people warn that Cairo traffic will be like. Previously, we’ve felt that despite the messiness of the picture, things have been managable.
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Today’s trip was like taken directly out of the lonely planet guidebook. Our guide Said Azawi (todo: double check last name) picked us up at the hotel at the appointed time. Driving over Gezira, past the Cairo Opera house and into Giza we arrived at the pyramids at the Giza Plateau early. We were a bit suspicious about the whole deal, but the guide recommended we get horses or camels to take us across the plateau.
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The “kobyuutr” on which I am writing this has an arab/english keyboard, so I will write in english) We arrived late at night at Cairo international airport, and got a first impression of Egyptian bureaucracy that has remained. We ended up standing in lines for a long time, and when we finally were through, it was 2 am, and we did not feel like dealing with Cairo’s infamous taxis. So we took a “limosin service” to the hotel.
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I am happy to see others express positive opinions about universal DAO interfaces in Java. Per Mellqvist writes in developerWorks: “Don’t Repeat the DAO” about creating a GenericDao interface: public interface GenericDao
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Due to popular demand, I will post a very short version of my Lazy Loading article: Why? Because this is bad: Category category = dao.get(1); Category parent = dao.get(category.parentId); int sumChildValue = 0; for (Long childId : parent.subcategoryIds) { sumChildValue += dao.get(childId).getValue(); } System.out.println(sumChildValue); This is good: Category category = dao.get(1); int sumChildValue = 0; for (Category sibling : category.get..
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Status: This article is currently pretty dry. I’d like feedback on how to make it more eloquent. In my previous blog post, I promised to write more about using databases as the main integration strategy. In the current post, I plan to cover maybe the most important question: “Why?” Imagine an application where every time it wants to communicate with another system, it reads or writes to the database. For now, let’s ignore how this would wor..
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The Intermedium of Tissue A variable represents a set of words in a particular order. For example, x might equal the word-set {the quick brown fox jumped over the lazy dog}. Note that the bracket represents the boundary of the word-set and is not included in the set itself. A piece of writing, whether it […]
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Before Web Services, there was CORBA. Before CORBA, there was DCOM. Before DCOM, there was RPC. Before RPC, there was BSD sockets. Before sockets, there were databases. And as it was in the beginning, so shall it too be in the end. The only systematically successful strategy in the history of computing is databases. I have discovered more and more lately that integration using a database is well-defined (DDLs - a WSDL that works!
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I really wish you’d stop using that word - I don’t think it means what you think it means.” (The Princess Bride - of course) When my wife asked “are you a feminist,” I realized I don’t like words very much. To some people, “feminism” means women who dress like men, think pornography is destroying society and that all men are inherently evil. You know the type I’m talking about. To many others, including my wife, a “feminism” is “the radical..
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Here are some of my favorite words. Signs of danger ‘Just’: bad word, as in “can’t we just develop the greatest application ever”, “can’t we just replace the database with JavaSpaces”, “can’t we just expose the functionality to the world as a web service”. ‘Should’: bad word, as in “it _should_n’t take more than a few days to do that, should it,” “integrating two systems should be easy.” Listen for use of this word from people who … should ..
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