SQL Server Express WebLog : General

SQL Server 2008 Upgrade Whitepaper

sqlexpress — Fri, 05 Dec 2008 20:50:00 GMT

The SQL Server Engineering team has released a masive white paper that details upgrading to SQL Server 2008. It's all good information, but if you're reading this blog you're probably interested in chapter 10, which specifically covers SQL Server 2008 Express. You can find more information here.

- Mike

Getting SQL Server 2008 Express on a DVD

sqlexpress — Mon, 10 Nov 2008 20:27:34 GMT

A small but persistent group of developers has been asking for SQL Server Express to be released on media, most commonly from those folks who live in areas without broadband Internet (yes, there are still such areas) for whom downloading an 80 MB package can be an endurance challenge. One of the benefits of the new setup framework in SQL 2008 is that you can now order a DVD that will allow you to install SQL Server 2008 Express. Don't go looking for the SQL Server Express DVD though, because you won't find it – rather, you just order one of the SQL Server Evaluation DVDs and install SQL Server Express from that.

You can start the process by navigating to SQL Server Trial Software page and clicking the "Download It Now" button for your chosen discipline. Have no fear; you will be presented with the option to choose between downloading and ordering on the next page. One caveat here, ordering the media is only available for folks in North America (sorry, I don't make those decisions). During the installation of SQL Server 2008 you are given the option to choose which edition you want to install and/or provide a Product Key. Lacking a Product Key you are allowed to install any of the free editions of SQL Server 2008. The edition combo box is defaulted to SQL Server 2008 Evaluation, but if you drop it down, you will find that SQL Server 2008 Express and SQL Server 2008 Express with Advanced Services are also available. Pick the edition you would like to install and you're on your way. Even though this is the Evaluation DVD, SQL Server Express does not have any kind of time bomb and it will function exactly the same as if you installed it from the downloadable package. Don't forget to register your copy of SQL Server Express.

BIDS or Bust: Writing reports in SQL Express 2008

sqlexpress — Wed, 27 Feb 2008 05:57:00 GMT

I asked for your oppinions about a new Report Designer in one of my earlier posts in this blog. I wanted to thank everyone for taking the time to offer feedback and for those of you who even filed a bug or two. As you've probably already guessed from the title, our ultimate decision was to stick with Business Intellegence Developers Studio for report design in SQL Express with Advanced Services 2008.

It's always a tough decision to make trade-offs between different scenarios and this case was no different. Stick with the rich, developer experience offered by the Visual Studio integration of BIDS or move to a more end-user focused experience that is friendly looking but doesn't have the developer features. (I know you're going to suggest that we just hand out both, but hey, it's a free product so you only get one. We have to share the new stuff with the other Editions too.) We desided to continue supporting the developer scenarios and will continue to offer BIDS are part of the Express family.

Not to worry, many of the advances in the design surface are shared between both BIDS and the new Report Builder. There are also some advances in Reporting Services Express it self, which I'll share when we're closer to releasing a CTP of that.

While the discussion about Report Builder is done, the February CTP has just begun. You can download it from here. (Bottom of the page under the Instructions heading. It's a bit hard to find on the page so keep looking.) I look forward to your feedback.

- Mike

SQL Server Express and Hosting

sqlexpress — Sat, 23 Feb 2008 04:49:00 GMT

Several questions have come up lately regarding whether SQL Server Express is an appropriate product to be used in a hosting environment. Here are the answers:

· User Instances (also known as RANU) available with SQL Server Express Edition, are NOT RECOMMENDED for hosting environments.

· Shared hosting: SQL Server Express Edition is NOT RECOMMENDED for shared (multi-tenant) hosting as the scale limits and memory handling do not allow it to meet the requirements of such an environment. SQL Server Standard Edition or Enterprise Edition are the best choice for shared hosting.

· Dedicated hosting: All versions of SQL Server including Express Edition are RECOMMENDED for dedicated (single-tenant) hosting environments. SQL Server Express Edition is a great way to provide a free copy of SQL Server with low cost Windows Server offerings. Where customers require more advanced features or higher scale, Workgroup Edition, Standard Edition, and Enterprise Edition are all options.

· Applications built on SQL Server Express Edition can be hosted in other editions of SQL Server. There is a tool called the Database Publishing Wizard (it comes bundled with Visual Studio 2008) to help the export/import process. If the Connection String contains a reference to User Instances, it needs to be updated (many sample applications and development tools include User Instances by default). There are several excellent post from Scott Guthrie that describe how to use the Database Publishing Wizard and how to post your ASP.NET application to a web host:

Recipe: Deploying a SQL Database to a Remote Hosting Environment

Update of SQL Server Database Publishing Toolkit for Web Hosting

Tip/Trick: How to upload a .SQL file to a Hoster and Execute it to Deploy a SQL Database

For hosters looking for more guidance on running SQL Server 2005 in a hosted environment, see the best practices article SQL Server 2005 Deployment Guidance for Web Hosting Environments.

Two posts in one day, I'm on a roll.

- Mike Wachal

- SQL Express team

Understanding SQL Express behavior: Idle time resource usage, AUTO_CLOSE and User Instances

sqlexpress — Sat, 23 Feb 2008 04:07:00 GMT

I've gotten a number of questions recently asking how SQL Express uses resources during idle time, and how that behavior impacts the way SQL Express behaves "on first connection" after being idle for a period of time. While many of these questions have been related to web hosting, the behavior is a general behavior for SQL Express, so I'll answer in general terms.

SQL Express: It's SQL Server with a twist

SQL Express is SQL Server. This may seem an odd thing to say, but many people get confused on this point, so I'll say it again: SQL Express is SQL Server. We have introduced some scale limitations to SQL Express and removed some features from SQL Express, but it is the same code base as all the other SQL Server editions. There are some specific places where we have changed the way SQL Express behaves compared to other editions and one case where we've introduced a feature that is unique in SQL Express (more on that later). I won't go into the details of which features are in which editions, you can find that information on the Microsoft web site: SQL Server 2005 Feature Comparison. This post is about those behavioral differences that lie just beneath the surface.

Idle thoughts about Idle time memory usage

SQL Server, in general, tries to return query results fast. This makes sense in terms of being a centralized, multi-user data service. When there are a whole bunch of users simultaneously asking questions, it's good to be able to answer those questions fast. One of the many ways SQL Server manages to do this is by caching frequently used information in memory. (That's as technical I'll get, you'll have to look elsewhere for a deep, technical discussion of the ins and outs of memory usage in SQL Server.) With SQL Express we wanted to target a different scenario, specifically, we wanted to support being a data store for single-user applications. This presents a different set of challenges, for one thing, there are long periods of time (call it idle time) when no one is asking any questions. The idea of holding a whole bunch of data in memory doesn't make as much sense if no one is going to be using it, and it might even be bad, because there may be other ways the computer could use that memory. So we made a change in the way SQL Express behaves:

When SQL Express is active it works just like any instance of SQL Server, data is cached in memory in order to improve the performance of subsequent queries.
When SQL Express is idle it aggressively trims back the working memory set by writing the cached data back to disk and releasing the memory. This frees up memory for other applications to use.

This behavior makes sense for a single user database engine - it supports higher performance when the application using the data is running, but once that application is shut down, memory is released to allow other applications to use it. I like to think of this as "being a good citizen" in the application community. There is always a catch when making this kind of trade-off though, and SQL Express is no different in this aspect. When SQL Express transitions from idle to active some of the memory that was released needs to be reclaimed; this results is a slight lag during "startup time" when you're first connecting to SQL Express. You can actually see this happening in the Widows Application Log, when you first activate SQL Express after some idle time, an entry is written to the log that reads like this:

Server resumed execution after being idle 16056 seconds: user activity awakened the server. This is an informational message only. No user action is required.

This is just telling you that SQL Express was idle and is now awake because some user activity woke it up. (When you think of it, it's kind of rude for users to keep waking up SQL Express without consideration for SQL Express's feelings. Maybe it's had a rough day and needs some rest!) This behavior is not configurable, it's just the way SQL Express is written. As mentioned above, this behavior change is unique to SQL Express, if you have need for your SQL Server to stay awake, SQL Workgroup or higher would be a more appropriate choice for your database engine.

This (data)store will AUTO_CLOSE in 300 milliseconds

Another minor change in SQL Express that has a lesser impact on perceived performance is the way the AUTO_CLOSE property of a database is handled. The AUTO_CLOSE property allows a database to be managed more like any other file in Windows by releasing the lock that SQL Server would normally hold on the file and allowing it to be copied, backed up, etc. This type of behavior is very important to supporting XCopy type deployment, which is a core piece of functionality needed to support Visual Studio ClickOnce™ Deployment. Supporting ClickOnce is something we wanted to do with SQL Express, so we modified the behavior of the CREATE DATABASE functionality in SQL Express in order to set AUTO_CLOSE to True for all databases. The results of this is that after 300 ms of inactivity for a database, SQL Express will close the database and release the lock on the file. It's important to recognize that Close and Detach are two different things. SQL Express still maintains metadata information about the closed databases, we just don't lock the file. When a request comes in that requires the use of a Closed database, we Open the database using the information stored in metadata. Opening a database that has been closed does not have a significant performance impact, but it can have some interesting side effects (and by interesting I mean negative) for certain kinds of operations:
If you are running an iterative process that includes a cross-database query and the period of the iteration exceeds 300 ms, the external database your process access would go through a Close/Open cycle during every iteration. This can add up over a large number of iterations and become a large component of the process.
If you have a process that polls a database at intervals, and that interval is larger than 300 ms, the database will go through a Close/Open cycle with every poll. In this case, the direct performance impact is negligible, but the fact that SQL Server writes an entry to the Windows Application Log every time a database is opened can result in your log filling up unexpectedly. (One example of this is if you have installed Reporting Services Express; it polls one of it's databases every couple of minutes.)

Happily, you have some flexibility here to address the behavior within SQL Express. The behavior of CREATE DATABASE in SQL Express is not configurable, it will always set AUTO_CLOSE to True, but AUTO_CLOSE is just another database property, so you can change that property once the database has been created. Read the BOL topic ALTER DATABASE (Transact-SQL) for more information about changing the AUTO_CLOSE property programmatically. You can also change this property using SMO and in the Database Properties dialog in management studio. (Interesting Trivia: When you create a database in management studio, there is some post-creation processing that happens to set the database properties to match what ever is in the model database. Since all system database have AUTO_CLOSE set to False, even in SQL Express, this results in databases created in management studio to have AUTO_CLOSE set to False, even for SQL Express, unless you've changed the properties on your model database.)

Net/Net - If you're using SQL Express as a standard multi-user server, you'll probably want to consider changing the AUTO_CLOSE property of your databases to False after you create them.

What is a RANU?

An electric car built in Seattle and powered with recycled Starbuck's coffee cups.
A small marsupial native to Redmond, Washington that lives in the beards of SQL developers.
A user specific process of SQL Express designed to allow non-administrative users to use SQL Server as the data store for Windows Forms based applications.

As much as I wish the answer were either 1 or 2, it is actually 3. RANU stands for Run As Normal User and is a feature that is unique to SQL Express. You've probably heard this feature referred to as User Instances. I'm not going to go into a detailed, technical description of User Instances, but will rather point you to the white paper on the topic, SQL Server 2005 Express Edition User Instances. I'll stick with the theme for this post and just discuss how RANU behavior impacts perceived performance and resource usage.

If you didn't read the white paper (feel free to do so now, I'll wait) it is important to understand that RANU is a separate process of SQL Express from the parent instance and that it has some additional limitations beyond SQL Express:

RANU supports only local connections via Shared Memory. (i.e. It's designed for single-user applications.)
RANU supports only Windows authentication.
RANU is a user specific instance, each user gets their own RANU instance that is not shared with other users. (i.e. The databases can not be shared between RANU instances.)

There are three basic issues to be aware of when consider how RANU impacts resources and perceived performance:
Since RANU is starting a separate user Process of SQL Express when an application launches, you have multiple copies of SQL Express running and using system resources. Most commonly this means there are two instances running, the parent instance and the RANU instance, for a computer with one user. (This could change, for example, on Terminal Services where you can have more than one user of the computer simultaneously.) RANU is tied to the User, not to the application, so while an application starting can result in a RANU instance being started, it does not shutdown the RANU instance automatically when the application closes. A RANU instance has a defined timeout value of 60 minutes; after 60 minutes without activity, RANU shuts itself down. The RANU timeout is configurable at the parent instances through the 'User Instance Timeout' setting.
The first time you start RANU for a specific user, SQL Express has to make copies of all the system database that will be used by the RANU instance. Making copies of these files can take longer than the default connection timeout value (30 seconds if you're wondering) and result in a timeout error. Behind the scenes, the file copy will finish and the RANU instance will starte, it's only the connection that fails. If you try the connection again, it will succeed. I find that changing the connection timeout to 60 seconds in your RANU connection strings handles this "first use" delay. (Your mileage may vary.)
On all subsequent connections to RANU for the same user (see #2 for the first time connection issues), there are two states, RANU may already be running having been started previously and not timed out yet or RANU may not be running, in which case it must be started. If RANU is not running, there is a short delay while the instances is started. I've not found this delay to be large enough to be noticeable within the context of other application load operations, and have rarely seen problems with the connection failing because of the lag, other claim there is a delay. Again, your mileage may vary, but changing the connection timeout to 60 seconds in RANU connection strings usually ensures a successful connection. The "start up lag" is part of the territory with RANU. You can consider the trade-offs of setting the User Instance Timeout to a longer period, thus reducing the number of occurrences of "start up lag", with the viability of keeping the dormant RANU instances running when it's not being used. (Note: RANU will trim it's memory usage when idle just like the parent instance of SQL Express, so you're really splitting hairs at this point.

That's quite enough for now, it's been awhile since I've posted anything and I guess I got carried away.

- Mike Wachal
- SQL Express team

Keeping Express up to Date

sqlexpress — Fri, 28 Jul 2006 06:07:00 GMT

Two of the tenets that were important to us as we designed SQL Server 2005 were called "Secure by Default" and "Secure by Design." These tenets are manifest in a number of ways throughout the product. Examples in SQL Express include the fact that we install the minimum components required to get a functioning database and that we don't enable network protocols in a default installation. (The issue of remote connectivity generates a bunch of question of it's own, but that's not today's topic. If I've peaked your interest, check out the KB article 914277: How to configure SQL Server 2005 to allow remote connections to learn more.)

Another important way to improve the security of an application is to make sure it is easy to update it to the latest version. In the language of the business, this is called "servicing" the application. We're going to improve the Servicing of SQL Express, when we release Service Pack 2, by making it available on Microsoft Update as a recommended update. Having SQL Express on Microsoft Update is a continuation of the work we started by making Service Pack 1 of the other Editions of SQL Server 2005 available on Microsoft Update. SQL Express will be detected when you scan your computer, right along with other Microsoft applications, and you will have the ability to select the update and have it applied to your computer. The other significant benefit of having SQL Express serviced using Microsoft Update is the ability to issue Critical Updates, should the need arise, and have them automatically downloaded and/or installed based on the setting on the computer. You will still be able to download the latest version of SQL Express from the SQL Express download page to install new instances.

This new servicing model has some ramifications for developers who include SQL Express as a component in their applications. Microsoft Update will detect and update all instances of SQL Express on the computer. Developers need to be aware of upcoming service pack releases and get involved in the Community Technology Previews for each service pack. Participation in the CTP and reporting issues is the best way to help Microsoft ensure that we don't break backwards compatibility in our service packs. Obviously, it's always our goal that existing applications continue to work, the CTP is a safety valve to help achieve that goal.

Before you even ask, I don't have any dates for Service Pack 2 or the CTP. I'll post them when I can. Keep an eye on the SQL Server 2005 Home Page and the SQL Server 2005 Developer Center for announcements and dates.

Mike

Best Practice Analyzer for ASP.NET

sqlexpress — Sat, 01 Jul 2006 03:33:00 GMT

Joe Morel, from the Developer Solutions team just blogged about the Alpha release of the ASP.NET BPA, a tool that will help users properly configure their ASP.NET sites.

Those of you that build data bound ASP.NET sites know that configuring the site for data access can be particularly challenging. I encourage you to read Joe's blog to learn about this tool and then download the Alpha release. You can help the Developer Solutions team out with this tool by posting suggestions to thier Forum.

Mike

Webcast on deploying embedded databases

sqlexpress — Fri, 12 May 2006 01:51:00 GMT

Update: Q & A from the webcast is available here. I'm still working on getting the source code posted. If you missed this webcast, you can view it on demand from this page.

---------------------------------------------

I'll be giving a webcast that describes how to deploy an embedded database using Visual Studio 2005 ClickOnce technology. The webcast will be at 1 PM Pacific time on Friday 5/12. You can register for the webcast here.

I hope you have a chance to log in.

Mike Wachal
SQL Express team

Demystifying the MSDE Workload Governor

sqlexpress — Mon, 13 Mar 2006 23:10:00 GMT

If you don't frequent Euan Garden's BLOG and you're interested in a history lesson on the Workload Governor in MSDE (and the fact that it doesn't existin in SQL Express), you should check out his recent post on the subject.

http://blogs.msdn.com/euanga/archive/2006/03/09/545576.aspx

Mike Wachal
SQL Express Program Manager

Various Downloads of Samples and Documentation for SQL Express

sqlexpress — Thu, 22 Jul 2004 09:00:00 GMT

MSDN has a downloads page specific to express:

http://www.microsoft.com/downloads/details.aspx?FamilyID=2adbc1a8-ae5c-497d-b584-eab6719300cd&displaylang=en

-Euan Garden

Product Unit Manager

SQL Server Tools

SQL Express Beta 2 coming soon

sqlexpress — Thu, 22 Jul 2004 03:27:00 GMT

The full Beta 2 version of SQL Express is coming soon. While the Beta 2 release will not add any new features, it does contain many bug fixes that were not in the Tech Preview. We recommend upgrading to Beta 2 as soon as it is available.

Unfortunately, the Beta 2 build requires a later build of the .NET Framework than the Tech Preview. You will need to uninstall the 2.0 Framework and download the updated version from the Express download page before attempting to install Express Beta 2. Also, SQL Express Beta 2 and Tech Preview builds cannot be installed side by side on the same machine. This means that if you have Express installed you will need to uninstall all the Tech Preview components before attempting to install Beta 2. You can find a preview of the download page instructions below:

· Step 1: Use Add/Remove Programs to remove any earlier version (lower than 9.00.852) of SQL Server 2005 components (if any). Remove all of the following components (if exists) in the same order as listed below:

Microsoft SQL Server "Yukon" Beta 1
Microsoft SQL Server 2005 Beta 2
Microsoft SQL Server 2005 Express Edition Beta 2
Microsoft SQL Server 2005 Tools Beta 2
Microsoft SQL Server 2005 Tools Express Edition Beta 2
Microsoft SQL Server 2005 Data Transformation Services Beta 2
Microsoft SQL Server 2005 Analysis Services Beta 2
Microsoft SQL Server 2005 Notification Services Beta 2
Microsoft SQL Server 2005 Reporting Services Beta 2
Microsoft SQL Server Setup Support Files
Microsoft SQL Native Client

Note: It is not necessary to remove previous versions of SQL Server such as SQL Server 2000, SQL Server 7.0 or any earlier versions.

· Step 2: Use Add/Remove Programs to remove Microsoft .NET Framework Versions 1.2 or 2.0, if installed.

Note: It is not necessary to uninstall Microsoft .NET Framework Versions 1.0 and 1.1.

· Step 3: Download and install the Microsoft .NET Framework 2.0 available at Microsoft .NET Framework 2.0 download center page.

· Step 4: Install SQL Server Express by clicking the Download button on the upper right corner of this page. SQLExpr.exe is a self-extracting installation package of SQL Server Express. Save SQLExpr.exe file to your computer.

Networking is disabled by default

sqlexpress — Sat, 03 Jul 2004 05:18:00 GMT

After seeing a number of issues about this, I realized that we needed to comment on this.

For SQL Express, all networking protocols except shared memory are disabled by default. There is a command line setup switch called DISABLENETWORKPROTOCOLS which is always set to 1 in SQL Express installations. You can override this by providing the switch DISABLENETWORKPROTOCOLS=0 to setup.exe on the command line. On an already installed machine, you can use SQL Computer Manager to configure the networking protocols.

The SQL Browser service is also not started by default *unless* the command line switch DISABLENETWORKPROTOCOLS=0 is passed to setup.exe. You can change SQL Browser's startup type by using the Services control panel.

-Jeffrey Baker
SQL Server Setup Development

Welcome to the SQL Server Express Blog

sqlexpress — Thu, 01 Jul 2004 19:05:00 GMT

Welcome to our team blog for SQL Server Express. In this blog we post answers, to frequently asked questions from our newsgroup (see below) and try to address any general questions or issues from the community.

Newsgroup: http://communities.microsoft.com/newsgroups/default.asp?icp=sqlserver2005&slcid=us

To submit bugs or feature request: http://lab.msdn.microsoft.com/express/sql/bugs/

Many Thanks,

SQL Server Express Team