Ralf's Sudelbücher

As explained in my previous postings, I implemented a local/embeddable version of the Amazon SimpleDB data model and API in C#. You can download the sources from my NSimpleDB Google Code Project and build the tuple space engine yourself, or you download the demo application which includes the engine as a single assembly: NSimpleDB.dll.

In my previous postings about Amazon´s SimpleDB data model and API I explained, what Amazon´s online database service - or to be more precise: tuple space - has to offer in general. If this sounds interesting to you, then now welcome to the desktop. Because it´s the desktop on which you can actually experience what it´s like to use such a tuple space. SimpleDB currently (as of Jan 08) is just in limited beta and you have to line up to get one of the limited test accounts.

Amazon´s SimpleDB is an exciting new player in the database world. It´s free, it´s online, it´s not relational. SimpleDB is a dynamic database implementing a tuple space. Currently SimpleDB (as of Jan 08) is in beta - but not everyone can get his hands on it. You have to apply and line up for one of the limited test accounts.

Have you heard about Amazon´s online "database service" SimpleDB? They describe it like this: "Amazon SimpleDB is a web service for running queries on structured data in real time." So it´s not a RDBMS, because Amazon does not call the data "relational", but just "structured". And you use a web service based API to access the data, not good old ADO.NET. Currently SimpleDB is in beta. You can get a test account to play around with it - if you´re patient. As of this writing (Jan 08) evaluation is limited; you need to apply and queue up to be assigned a test account. I have about 2 weeks ago, but haven´t heard from Amazon since then.

When writing more complex code you cannot really step through during debugging, it´s helpful to put stud it with statements tracing the execution flow. The .NET Framework provides for this purpose the System.Diagnostics namespace. But whenever I just quickly wanted to use it, it turned out to be a hassle to get the tracing running properly. That´s why I wrote down the following, to make it easier next time.

My previous posting on Software Transactional Memory (STM) I concluded with the remark, NSTM was not finished. How true! Here is the next release of NSTM with a couple of improvements. You can download it from Google´s project hosting site. Here´s what´s new:

The API for my .NET Software Transactional Memory (NSTM) I´ve described so far is straightforward, I´d say. It´s close to what you´re used to from transactional dabase access and it´s even integrated with System.Transactions: open a transaction, do some stuff with transactional objects, commit the transaction. All very explicit.

So far I´ve described my own .NET Software Transactional Memory´s (NSTM) API for managing transactions. It´s close to what you are used to from relational databases, I´d say. But still, it´s my own API and it stands beside what .NET already provides in terms of transactions. With System.Transactions there is already a general way to work transactionally across different resources like database and message queue, so it would be nice if NSTM was another such resource.