Happy 2012 to all of you! 2011 has been a great year. We now have federations live in production with SQL Azure. So lets chat about fanout querying. What is a fan-out query? Federations provide a model for partitioning parts of your schema over to multiple member databases for harnessing scalability of many nodes. However applications still need for querying all of the data across federation members. Fan-out is a technique for querying data in your federation, across many federation members. Fan-out queries are much like map/reduce in that it is formed in 2 parts;
Member query is the piece that is sent over to all members involved in the query and Summary query is the query that is the post processing piece to allow condensing the results from the member query to desired final result-set. With fan-out queries the member query is always there but summary query may not be needed. For example if you are simply doing DML (we’ll have some examples like data pruning or reference data management etc) or DDL (we’ll look at schema deployment in detail below), fan-out would only have...(Read whole news on source site)
A couple of months ago, I posted a list of my F# talks and courses for Autumn 2011. Although I tried hard to have fewer speaking engagements during the winter and spring, there are quite a few events that I'd like to invite you to. Last year, I spent quite a lot of time talking about asynchronous programming and agents. I think this is still a very important topic and especially agent-based programming in F# is a powerful way to implement concurrency primitives (like blocking queue), as well as complex systems (like
We have released the final preview of the Code First Migrations work as part of Entity Framework 4.3 Beta 1. This post will provide an overview of the functionality that is available inside of Visual Studio for interacting with migrations. We will focus on the code-based workflow for using migrations. In this workflow each change is written out to a code-based migration that resides in your project. There is a separate EF 4.3 Beta 1: Automatic Migrations Walkthrough that shows how this same set of changes can be applied using a mixture of code-based and
automatic migrations. This post assumes you have a basic understanding of Code First, if you are not familiar with Code First then please complete the Code First Walkthrough. Building an Initial Model Before we start using migrations we need a project and a Code First model to work with. For this walkthrough we are going to use the canonical Blog and Post model. Create a new MigrationsCodeDemo Console application.
. Add the latest prerelease version of...(Read whole news on source site)
At the end of November we released Beta 1 of Code First Migrations. At the time we released Code First Migration Beta 1 we also announced that we would be rolling the migrations work into the main EntityFramework NuGet package and releasing it as EF 4.3. Today we are making Beta 1 of EF 4.3 available. This release also includes a number of bug fixes for the DbContext API and Code First. We are planning for this to be the last pre-release version of migrations and our next release will be the final RTM of EF 4.3.
What Changed This release has been primarily about integrating migrations into the EntityFramework NuGet package, improving quality and cleaning up the API surface ready to RTM. Notable changes to Code First Migrations include: New Enable-Migrations command. You now use the Enable-Migrations command to add the Migrations folder and Configuration class to your project. This command will also automatically fill in your context type in the Configuration class (provided you have a single context defined in your project). Update-Database.exe command line tool. In addition to the power shell...(Read whole news on source site)
C# is a wonderful language for modern programming. While everything in C# has a reason and a place, occasionally there are things that can be confusing for a developer who isn’t aware of what is happening behind the scenes. This is another post in the Little Pitfalls series where I explore these issues; an index of the Little Wonders and Little Pitfalls posts is here. This week will be a short post since I’m travelling to Denver for design meetings, and otherwise spending most of my free time celebrating a birthday with friends and family.
But I had a quick item to share that I’ve seen come up more than once on SO, so we’ll add it to the Little Pitfalls. The System.Diagnostics.Stopwatch class is very useful for elapsed time measurements in .NET applications. Today we’ll look at the ElapsedTicks member of the Stopwatch class, and some of the confusion of what this quantity represents, especially compared to TimeSpan or DateTime Ticks. The Stopwatch Class While DateTime is fine for getting the current value of the date and time, it is not exactly precise or lightweight. Thus, when timing a process,...(Read whole news on source site)
Implicit data templates are a new interesting feature of Silverlight 5.0. They are a new way to create templates that automatically applies to specific types. So, imagine you have a set of types defined, and you want to present a collection of them inside an ItemsControl, you can use an Implicit Template that apply to each one of the types you are binding. Automatically this template will be applied to the give type every time it appear in the collection. As you can figure out if may become really useful to present every item in a different
way. Let say you have an Event base class and two derived Alarm and Information. You can bind the ItemsControl to an ObservableCollection