July 2004 - Posts
I am a very believer that engineering, and life, is about tradeoffs. It is rare indeed when there is an “alway true” right answer. Ask anyone who has taken any of my training courses - the answer to almost any question, expecially if if begins with “Which way is better...”, is “it depends” ! The answer to all other questions is “XML” ! :-)
In order to make the right tradeoffs, you need to know what your options are and what are the plusses and minusses of each one. Here is a good start on the question of when to use Web Services (ASMX), Enterprise Services (ES) or .NET Remoting. There are some good embedded links, which I give you here and here as well.
Here is an excellent overview to the new XML and XSL editing and debugging tools in VS 2005. The blog post includes links to addtional information, including a more detailed white paper on MSDN.
If you are an MSDN Subscriber, SQL Server 2005 Beta 2 is now available for you to download on the MSDN Subscriber Downloads site.
Also available for public download is SQL Sever 2005 Express Beta 2. This contains mainly bug fixes to the recently posted SQL Sever 2005 Express Technical Preview.
If you are upgrading from the Technical Preview to Beta 2, be sure to first follow all the steps listed on the download page as upgrading. Of course, if you are using a VPC (as you should be) , it should be much easier... :-)
Here is a link to a posting on how SQL Express Xcopy Deployment works.
One thing I would add is to show what the connection string would look like. This answers the question of how does the application know where to find the database file ? The answer is actually quite simple - just as with an MDB database file, when you are using the file-based approach to accessing SQL 2005 Express you include a path to the physical file in the connection string for the new AttachDBFileName parameter:
Dim ConnStr as string = "Data Source=.\SQLExpress; Initial Catalog=; Integrated Security=true; AttachDBFileName=" & Application.StartupPath & "\MyDb.mdf "
Connecting with this connection string causes the file MyDb.mdf to be automatically attached to the SQLExpress instance. When the application ends, it will automatically be detached and therefore not locked and available for copying.
For example, if your .mdf file is located at "C:\Program Files\My Application\MyDb.mdf", then SQL Server Express will assign a logical database name that exactly matches the path:
C:\Program Files\My Application\MyDb.mdf
and what you'll see in the Server Explorer is
ServerName\sqlexpress.C:\Program Files\My Application\MyDb.mdf.dbo
You have probably heard already about the Visual Studio 2005 Express family of products that were publicly revealed at TechEd Europe. This is a set of 6 products (VB, C#, J#, C++, Web Developer, SQL Server) that will be available for very low cost. More important, however, is the fact that each of these versions goes out of its way to make it easier for the inexperienced .NET developer to quickly be productive. It starts with the fact that the download size is significantly smaller, setup time is fast, and the IDE is designed to make the first experience(s) as smooth as possible. Another cool feature are the Starter Kits that are included. The VS team is taking a page out of the ASP.NET playbook and providing their own starter kits. These are fully functional sample applications that come with tutorials, along with the source code. The Beta 1 version of VB Express already comes with the My Movie Collection starter kit. Of course, the idea is not only to learn from the starter kit, but also to take it further and extend/modify it to meet your own needs.
But what I really want to talk about is SQL Server Express :-)
This is the replacement/next generation of MSDE. If you're not familiar with this, it is a free and redistributable version of the SQL Server engine (SQL 2000 in the case of MSDE and SQL 2005 in the case of SQL Express), without the tools and additional services, and a few limitations. I have always been a big fan and proponent of MSDE, and have pushed my clients to use this instead of an MDB, except for the simplest of applications.
On the SQL Express page you can see the long list of features of this product - I 've also pasted it here for you.
A robust database for building dynamic applications
- Based on the core SQL Server 2005 Database Engine, including an advanced query optimizer and the new snapshot isolation level
- Supports the complete SQL Server programming model including T-SQL and CLR integration
- Standard SQL Server objects such as stored procedures, views, triggers, and cursors
- Client (Subscription-only) replication and support for the new Service Broker features
Strong XML support
- Native XML data type
- Supports structured and semi-structured data
- XQuery support
- XML Schema support
Tools and features to enhance management and ease of use
- Automated tuning of database parameters based on usage characteristics
- Express Manager (coming soon) will provide wizards for many common tasks
- Comes with Computer Manager for starting and stopping the SQL Server Express Windows service
- Automated servicing and patching (as part of Microsoft Update)
- XCopy deployment with administrator privileges (non-admin support in Beta 3)
- Simplified documentation helps you easily build dynamic applications using relational databases
Easy installation and setup
- Fast download
- Simplified user interface for setup
- Silent install for embedded usage
Scalability and performance
- Supports 1 CPU, but can be installed on a server with any number of processors
- Maximum 1 GB addressable RAM
- Maximum 4 GB database size
Deep integration with Visual Studio 2005
- Installed with Visual Studio 2005
- Takes advantage of Visual Studio Data Explorer for designing schema, adding data, and querying local databases
- CLR integration
- Supports user-defined types and aggregates
- In-process data access with ADO.NET 2.0
- Integration of SQL Server and CLR security
- Integrated debugging
- Secure by default settings
- Fine-grained administration rights
- Three levels of code access security: Safe, External Access (verifiable), and Unsafe
- Supports leveraging stored procedures as an abstraction layer
- Support for Windows authentication
If you look carefully, you'll notice that almost everything is not specific to SQL Express, but rather, a feature of SQL Server 2005 (this is a good thing!). However, I think that there are 3 areas that deserve special notice – I have highlighted these in red for you. These are, IMHO, the 3 biggest difficulties in getting people to move from MDB to MSDE today - and have all been addressed in SQL Express:
(1) Difficult deployment - having to learn at least the basics of administering SQL Server
(2) No tools for manipulating/querying the database once deployed - even though you can use Access or the tools in VS during development
(3) Performance limitations - mainly concerns about the performance governor - an artificial limitation on performance when there are more than eight active concurrent operations.
These issues are addressed in SQL Express in the following manner:
(1) XCOPY deployment. This means that to deploy a database on a new machine (or different location) all you need to do is copy the MDF file and modify (maybe) the connection string. This is exactly what you need to do with an MDB – and no more. No need to create or attach a MDF to create a logical database. No need to open any SQL administration tool.
(2) There will be an easy to use administration tool for SQL Express – called XM (Express Manager) that will also be free and redistributable.
(3) Although there are still a few, IMO very reasonable, limitations that affect performance, the workload governor has been eliminated! This eliminates much of the mystery and guesswork surrounding performance.
For many applications, at least most of the ones for which I do recommend the use of MSDE today, the performance issue is more a matter of fact than reality. In most applications that should be considering using MSDE, the performance hit will be negligible, if anything. Of course, there are many applications, if not most production database applications, that do need to go beyond MSDE/SQL Express to the full-fledged SQL Sever product. If not, Microsoft would not be investing massive amounts of money and resources into this product…But until your application truly requires the advanced performance/features, get started on the right foot for free, with MSDE or SQL Express. Or have both a high-end and a low-end (or trial) version of your product.
About a year ago, I was able to convince a client of mine of all of the benefits of MSDE and that they should use that instead of an MDB in their current system. He was convinced of everything - except for performance. We agreed that they would try to simulate their current workload and then do some performance and load testing. Needless to say, they are now happily using MSDE in their application.
With SQL Server 2005 Express, you not only get the features of SQL Server 2005 (Yukon), but the main objections to MSDE have been eliminated.
Talk about a no-brainer…
Although this year's annual TechEd Europe event is a few weeks behind us now, I am just now finally catching up from it. While other speakers also felt that this year was unusually hectic and pressured, I know that for me it particularly so. This was mainly due to the fact that my schedule was REALLY packed. First of all, I was giving 5 different sessions - 2 of them at 8:30 in the morning ! It was a nice mix of 2 "regular" presentations, 2 Birds Of a Feather sessions, and 1 Chalk & Talk.
The sessions were:
DEV305 Building with Blocks is Quick, Easy, and Reliable
DAT331 Notes from the Field: ADO.NET
CHT012 VB6 Upgrade Clinic
BOF010 Now What Are They Going to do to My VB ?
BOF006 MS Patterns & Practices – are they relevant to me ?
It was nice that I had the opportunity to present and talk about three of my current passions/areas of expertise: VB.NET, ADO.NET, and Patterns & Practices.
The smaller, interactive sessions are always fun, but challenging. Especially the Birds Of a Feather (BOF) sessions, since there isn't even a projector in the room. Part of the problem with BOF sessions is that people don't really know what it is or what it is supposed to be. In fact, I was pretty surprised by the makeup of the audiences in my 2 Patterns & Practices sessions. The BOF had mostly people who knew little about P&P, and wanted to learn the basics. In my "regular" presentation on the Application Blocks, most of the people were familiar and experienced with the Application Blocks. The makeup of the audiences should have been exactly the opposite !
In between giving sessions, I was trying to sit in on a few sessions as well. Unfortunately, I wasn't able to catch as many as I would have liked, since I also had meetings scheduled with various MS people - and other colleagues and friends.
Well, it is long, long overdue - I am finally writing my first blog entry. I have a feeling that my relationship to my blog will be similar to that with my cell phone: I was not an early adopter, but within a very short period of time, I was unable to imagine life without it !
One of my biggest fears/concerns is that I did not want to start a blog, and then just not be able to keep up my postings in a reasonable fashion. I don't guarantee a daily posting, but I do hope to be posting on a regular basis. At this point, I already have a bunch of things in my head and I'll just start letting them come out slowly...
What will be the style/content of this blog? I am aiming for mostly original technical postings, together with some good pointers to existing technical content, and a "pinch" of personal musings mixed in. Of course, I hope that it will be of interest to enough people so that there will be a good level of discussion.
I don't want to bore you with my biography. If you are interested, you can check it out at my company's web site: