MS SQL Server Pivot Tables

Another one for the "don't lose me" pile...

MS SQL 2005 and onward have a PIVOT function, which acts like an Excel pivot table.

Notes here.

Statistical Data Mining Tutorials

Just a little note to myself to not lose this link.

Tracing Internet Explorer

eJohn has this article discussing dynaTrace Ajax, a utility for IE6-8 performance tracing. Sounds like neat stuff:

Not only can you see the execution count for your defined JavaScript methods but you can also see execution time for the built-in DOM methods! Wondering what native method calls are slowing down your application? Wonder no more. From the HotSpot view you can filter by DOM or regular JavaScript and see exactly where execution time is going and what methods are so slow.

Worth a look.

25 Tips For Intermediate Git Users

Nice little list of stuff about git.

Read it here.

Live failover for Xen images

Remus promises to bring to the Xen hypervisor live failovers. In other words, if a host system crashes, another machine picks up the load without any interruption to services.

From the Remus website:

Remus provides transparent, comprehensive high availability to ordinary virtual machines running on the Xen virtual machine monitor. It does this by maintaining a completely up-to-date copy of a running VM on a backup server, which automatically activates if the primary server fails. Key features:

• The backup VM is an exact copy of the primary VM. When failure happens, it continues running on the backup host as if failure had never occurred.


• The backup is completely up-to-date. Even active TCP sessions are maintained without interruption.


• Protection is transparent. Existing guests can be protected without modifying them in any way.

This is neat because the only thing that I know of that provided this functionality is VMWare, which costs big bucks (and still holds the tools advantage). Xen is free, and available for Linux and OpenSolaris.

Open Data Kit

The University of Washington's "Change" project has just announced a collection of tools to simplify the development of data-collection applications. Called the "Open Data Kit", the primary client target is the Android operating system (no surprise, since Google was heavily involved).

Anyway, Change hopes to help out the third world with these tools, as cellular connectivity is often the only connectivity. That's a noble cause, but it is sure to have less-altruistic uses, as well. All open-source, under the Apache license.

Here's their rundown of the goodies:

ODK Collect is powerful phone based replacement for your paper forms. Collect is built on the Android platform and can collect a variety of form data types: text, location, photos, video, audio, and barcodes.

ODK Aggregate provides a ready to deploy online repository to store, view and export collected data. Aggregate is currently implemented on Google App Engine and enables free hosting of data on Google's reliable infrastructure.

ODK Manage maintains a database of all phones in a deployment to enable remote device management. By sending an SMS to a deployed phone, Manage can trigger the transfers of forms, data, and applications.

ODK Validate ensures that you have a OpenRosa complaint form -- one that will also work with all the ODK tools.

ODK Voice facilities mapping XForms to sound snippets that can be played over a "robo" call to any phone. Responses are collected using the phone's keypad (DTMF) and are automatically aggregated.

JVM on Xen, from Sun

This could be neat.

Sun has a project where they are trying to run a JVM directly on a hypervisor, without the normal OS in-between.

From their project overview:

Project Guest VM is an implementation of the Java platform in Java and hosted directly on the Xen hypervisor, that is, without the traditional operating system layer. It is based on the Maxine Virtual Machine which is itself written in Java. The result is a Java platform software stack that is all Java except for a very thin microkernel layer that interfaces to Xen.

Briefly, the goals for Guest VM are:

* Exploit access to low-level features, particularly memory management and thread scheduling.

* Enable specialization and optimization of the entire software stack.

* Simplify administration by extending the Java platform to replace the OS.

* Increase developer productivity through the use of modern IDEs.

More information, including instructions for getting the source code, can be found at http://research.sun.com/projects/guestvm.

If it is a single JVM per dom-U, then this could make resource provisioning a snap.

LiquiBase - Database Version Control

If you're a fan of Ruby on Rails, then you probably know about migrations (and what a pain they can be).

Well, LiquiBase promises to bring the same benefits (and headaches) associated with Rails-style migrations. I haven't had a chance to check it out, yet, but I will update when I do.

SocketShifter - Redirect Sockets on Windows

A trick I've often used to get around firewalls is ssh port forwarding. Basically, after SSH connects to a server, you can get it to forward local ports through the tunnel to arbitrary ports on the other end.

So, if I connect from work to my ssh server listening on my home router, I can forward my local port 1000 (which isn't being used) to port 80 on one of my internal machines, and connect to that webserver via http://localhost:1000.

Windows servers don't have many good options for an ssh server. The only one I've used was the version that comes with Cygwin, and it wasn't really all that good (hangs, crashes, non-killable).

Introducing SocketShifter, an app that performs a similar magic, only on Windows.

But wait, there's more!

It uses something called the .NET Service Bus, an offering from Microsoft's Azure. This promises to allow two machines to connect, regardless of intermediate firewalls (and how do I prevent this?). It also means you have to sign up for an account in order to use it.

I'll be sticking with ssh, for now, but this service bus thing looks kind of interesting.

Eucalyptus - AWS Workalike

I keep rediscovering Eucalyptus, an project aiming to be a clone of Amazon Web Services. I need to give them a real test run...

Crypto Provider Library

I'm going to need some encryption love soon, but I know better than to trust my own code for it.

Here's something I found for C#.