Handling GUID's (UniqueIdentifiers) in DB2 using VB.NET

Continuing the saga of DB2, I am now trying to handle GUID's/UniqueIdentifiers from the Enterprise Library. First thing I had to get a handle on is that DB2 UDB has no datatype similar to a GUID. In Microsoft SQL they are represented as UniqueIdentifiers and used quite extensively. Oracle represents them as RAW(16). When I ran the conversion on my database using the IBM Migration Toolkit (MTK), the GUID's in my database were converted to CHARACTER(16) FOR BIT DATA. So basically, a container to hold 16 bytes worth of data. It takes 2 hexadecimal characters to represent 1 byte so 32 hexadecimal characters is 16 bytes or 128-bits.

IBM DB2 on Fedora Core 3 64-Bit

I have moved on to my next adventure in writing a native database interface. We have decided to add native DB2 support to our product offering. I was fairly excited when I first started out to install this but after 5 days, I am frustrated and dismayed at the lack of forethought or testing put into the product. I downloaded DB2 8.2 from IBM's web site and installed the 90-day trial for enterprise edition on my Sun Sunfire V20Z development server running Redhat Fedora Core 3, 64-bit edition. Now I bet there are alot of people who want to test DB2 under these types of conditions and from what I read, it just won't work.

Callvantage QoS

I finally got around to fixing the QoS problem with my Callvantage VoIP setup. After determining about 3 months ago that my Callvantage box was dropping packets and causing general outbound havok on my system, I decided to move it inside my network behind my trusty linux firewall/router/mailserver/gameserver box. The unfortunate side effect was that I lost the Quality of Service capabilities. This caused a serious delay in voice transmission and sometimes even stuttering while I was talking on the phone. I usually just accepted it until my friend got his new Actiontec router and it handled VoIP QoS automatically. Now if Actiontec can do it, I know my outdated Redhat 7.3 install should be able to.

Coaxial Run with Power CCTV Troubleshooting Guide

Written by Jim Shank 8/2/05

 

There should be two major troubleshooting points for CCTV, the camera’s themselves and the central terminating location (CTL) in which the video signal is captured and the power is supplied (if power is not supplied mid-run or directly at the camera location). Troubleshooting will be started at the CTL and then move to each individual camera. It helps to have a baseline camera that is working in order to capture normal readings for comparison. Remember that CCTV cabling should be as follows

		RG-59/RG-6		UTP with Baluns		Fiber Optic
Run Length		< 250 ft.		250 – 3000 ft.		> 3000 ft.

 

Tools Needed

• Digital Volt Meter (DVM)


• Electrical Tape

Optional Tools

• BNC or F-type connector and small piece of coax


• 9V battery

 

.NET Remoting and App.config files

I am moving on to some remoting applications in my project and found another interesting tidbit. Almost all of the remoting examples in Microsoft .NET Distributed Applications: Integrating XML Web Services and .NET Remoting use console applications as component hosts (listeners) and of course call the RemoteConfigurationFile.Configure method. This really doesn't make sense since in the real world, you are probably going to be running your component host as a service. What isn't revealed is that when you start your service, it's local directory is your system dir (e.g. c:windowssystem32). In order to access your application configuration you either need to hard code the whole path (bad idea) or use the ever so handy AppDomain.CurrentDomain.SetupInformation.ConfigurationFile. This makes it much simpler to access the app.config file and load your remoting configuration correctly. I found a snip that this information is included in Ingo Rammer's Book Advanced .NET Remoting in VB.NET but I haven't read that one yet.

Systray icons here to stay

For almost a year now, I have been having problems with my system tray icons disappearing intermittently after startup. I assumed one of the 30 or so startup applications was crashing dropping the explorer process and therefore, only the following tray icons were appearing. I finally had some free time and was in the process of looking for a program to debug the startup process when I hit an interesting link. Apparently, this is a more common issue than I thought, so common that there is a fix called the Ostuni Workaround detailing that disabling the UPnP subsystem will fix the problem. I couldn't really believe that one thing had to do with another but after following the directions and a quick reboot, the problem went away. 5 reboots later, still no problem. I don't have to wait an hour to login or do any other voodoo to get this working. As a nice side benefit, I noticed that the system appears to be running faster. Network browsing is quicker and no longer hangs showing UNC and description of My Network Places. Absolutely great!

512MB MiniSD Finally Arrived

Like a watched pot left forgotten on the stove... the 512MB MiniSD card for my MPx220 finally arrived today. I had forgotten to call and check when the next "back-order" date would be for it and sure enough, it came. Nothing exciting to tell, it seems to hold 512MB so I copied a bunch of MP3's onto my phone. Since I now own the Motorola HS120 Stereo Headset (Headphones and microphone) I have a full blown 512MB MP3 player with me at all times. Sweet.