Monitors can be calibrated to display the “correct” colors by using a calibration device, complemented by the vendor software. I decided to buy the Spyder2Express since it had good reviews and a reasonable price. Unfortunately, there is no color calibration device that is supported on Linux by its vendor and I currently use Linux (openSuse) as my main operative system. I could use my work laptop running windows to calibrate the monitor, then export the color profile and import it in Linux. There is an article here on how to do it. With help from one of the comments in that article, I found about Argyll Color Management System. Argyll is a monitor calibration software package for Linux that supports most of the existing calibration devices. It uses the Windows binary software to create a Linux binary in order to be able to communicate with the device to run the calibration tests and create a color profile. It also provides an utility to apply the color profile to your monitor.

The steps to calibrate your monitor in Linux using Argyll are pretty simple. In my case, using the Syper2Express device, all I had to do was runt the following commands(as root, or give the user permission to communicate with the usb device):

$ cd Argyll_V1.0.3/
$ ./spyd2en -v /media/ColorVision/setup/setup.exe (creates binary file to communicate with device)
$ ./dispcal -v -y l -o MyMonitor (runs calibration tests and creates monitor color profile)
$  ./dispwin MyMonitor.icc (applies color profile to monitor)

The generated color profile can also be imported to your post processing software like GIMP in order to use the monitor color profile instead of using a more common profile like sRGB or Adobe RGB.

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For me, the need was only to change some photos info so that it shows the real time they were taken, three hours before the saved setting. The command was as simple as this:

exiftool -DateTimeOriginal-='0:0:0 3:0:0' -CreateDate-='0:0:0 3:0:0' myfolder/

The format for date changes is ‘YYY:MM:dd hh:mm:ss’.

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I currently develop mostly in Windows using Eclipse, so I decided to create an openSuse 11.0 vmware image to test some of my code, as our product supports various platforms, including some flavors of Linux. The 10GB disk size soon became too small and now I need to increase it. Here are the steps I had to do:

To resize the guest Os hard disk size, I issued:

vmware-vdiskmanager -x 15GB opensSuse.vmdk

However, step 1 only resized the disk, not the partitions. Starting the partition manager from within the guest Os didn’t work, because the partition can’t be altered while it is still mounted. A simple solution to overcome this issue is to use a Live CD. I still had the openSuse live CD ISO image I used to install the guest Os, so I just pointed the guest OS cd-rom drive to that .iso file.

After booting from the CD-ROM drive, go to Yast -> System -> Partitioner , select the partition you want to expand and click Resize. Select the new size for the partition and click Ok to apply the changes to the partition table.

Reboot your machine and voila! You existing partition will now have the new size.

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• usually it takes me 40 mins door-to-door. Not too bad, considering that the driving time was something between 15-30 minutes, depending on the luck with the 21! traffic lights between home and work (other than that, the drive was a monotonous 9 miles straight, right turn, 1 mile, arrived);
• instead of losing 30-60 minutes driving to work every day, I actually found myself with 1h20 of free time to do some productive stuff like reading or listening to podcasts.

Of course there are always drawbacks:

• the bus runs every 15 mins, light rail every 12 and shuttle bus to IBM about every 30 mins. If I get it right, I get from one place to the other in 40 mins. If I get it wrong a.k.a, lose the first bus or lightrail, it takes at least 30 mins more (have to catch next shuttle, if I get there on time).

But the goal of this post is not really to dicuss about VTA’s schedule, but instead about podcasts, more specifically, IT podcasts. I have been alternating between reading and listening to podcasts during the trip, and the podcast I have been listening to is Software Engineering Radio. It is an excellent podcast, and I’m still in episode 30, so have a lot to go (they have 103 as of today ). However, I’m looking for other series to mix up with this one, and also because I might skip some of the episodes that are not of my interest.

So, what IT podcasts do you listen to and what do you like about them? I recently added two series to amarok, but haven’t listened to any episode yet:

• IBM developerWorks podcasts
• Jon Udell’s interviews with innovators

Don’t forget to leave your comment and let me know what are your favorite IT podcats!

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It definitely is! Mylyn is a task manager that changes your IDE context based on tasks. You create a task, add resources to its context and when you activate the task, it hides all the other (unneeded) resources from your views (project/package explorer, outlines, editors, etc…). It provides integration with several task repositories, like Bugzilla and Trac. Unfortunately, it doesn’t provide a connector to Clearcase, but I’m still able to use it in an automated way.

I find the tool really awesome when I do something basic like switching tasks: it just closes all the editor windows and projects in the explorer for the task I’m leaving and opens all the files I was working on for the task I’m switching to. This would take me several minutes to do by myself, so having a tool that does that in 1 second is pretty neat!

Here are some more things I like about Mylyn:

• ability to customize CVS/SVN checkin comments based on templates. Most, if not all, of my commit comments are in the form of “Bug#xxxxx: 1 line description of the bug and fix”. With Mylyn, I can get the comment populated automatically with information from the associated task.
• when I (re)activate a task, it positions the cursor in the file and method (if java file) I was working on.
• I can use the URL feature to link to the Clearcase defect page for each one of my defects
• dynamically adds resources as we follow method references
• Mylyn filters unrelated content from all views, but I especially like the end result for the package explorer and outline view. When working with classes that have tens of methods, showing just a handful of them in the outline simplifies things a lot!

And the things I don’t like that much:

• no connector to Rational ClearCase. I have to copy some notes and Defect info from Clearcase to my task manually.
• the option to show filtered content only shows content at the same level. I would like to have a “show all” option for when I need to look for some resource.
• It slows down the system a bit. Not too bad, but I do notice it when I have several eclipse instances running.

Overal, I think Mylyn is a great tool and very useful! Even more if you are working with Bugzilla/Trac projects.

If you want to give it a try, this is Mylyn’s homepage and this is a Mylyn tutorial.

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It contains links and summary to tens of other performance articles related with java database application development.

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From the conversations I have had with both DBAs and developers, it is clear that DBAs prefer static SQL, while developers prefer Dynamic SQL.

The difference between static and dynamic SQL is that static SQL needs to be compiled and bound to the database before application runtime, while dynamic SQL is compiled during runtime. Next, I’ll show a list of pros and cons regarding each one. 

Static SQL

Pros:

• compile at bind time. Since the statement is compiled only once and before we run our workload, we have all the database resources in order to generate the most optimal query execution plan. In DB2, there are 9 levels of optimization, being 5 the default one. When we bing our application package, we can pick the highest optimization level - 9 - and get the most optimal execution plan. Using a higher optimization level requires more resources for the compile phase, but since our workload is not yet running, we can afford this high resources requirement.
• security. Security is probably the most common reason why people use static SQL instead of dynamic SQL. Static SQL allows the DBA to set authorization at the package level. For example, consider an application package app1, that provides SQL functionality to select employee’s name and address from the table employees. The DBA can five user JOHN execution privileges on package app1, even if user JOHN does not have SELECT authority on table employees. Static SQL provides a much finer layer of security.

Cons:

• need to bind before runtime. Although binding before runtime usually allows for more optimized access plans, doing this in a test or development environment can be cumbersome.
• lack of tooling support. most of current IDEs provide coding assistance with support for APIs like JDBC. The lack of support from development tools discourages the use of static SQL.

Dynamic SQL

Pros:

• IDEs and APIs: using eclipse to develop Java code that interacts with the database using JDBC or JPA is much simpler than developing a SQLJ application.
• statement caching. Dynamic statement caching avoids the need to compile the same statement multiple times, increasing the performance to values close to static SQL. However, bear in mind that a cache miss will be extremely expensive.

• better statistics. Because the statement is compiled at runtime, it uses the latest statistics available, contributing to a better execution plan.
  

Cons:

• compile at runtime. There are a few reasons why compile at runtime can be a bad thing:
  
  • every time a statement is executed, it needs to be compiled, increasing the total statement execution time
  • the compile time will account for the total execution time, so using higher optimization levels may slow down the overall performance instead of improving it.
    
  • because the statement is only compiled at runtime, errors in the SQL statement won’t be detected until runtime.
    

As you can see, there are several reasons why you would choose one over the other. There is no perfect solution! But if you ask me, I would suggest the following: use Static SQL if security is your main concern and use Dynamic SQL if ease of development is your main concern.

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