Application Modernization: What Is It and How to Get Started
The following is Chapter 3, "Enterprise Data Management," from SQL Server 2005 Distilled by Eric L. Brown, published by Addison-Wesley, ISBN: 0321349792.
In the beta history of the SQL Server 2005 release, significant emphasis has been put on the new features for developing applications. Let's just say that Microsoft loves developers. But what happened to the features for those who get paged in the middle of the night when mission-critical systems hang? This chapter looks at features for the unsung heroes of corporate IT—the database administrator (DBA). For the DBA, SQL Server 2005 will change everything about the way administration is accomplished.
This chapter covers what's new in enterprise database administration. It doesn't just look at the product from a feature list, but groups the features according to some tasks common to database administration. This chapter specifically discusses the following:
- Infrastructure management. How do installation and configuration work?
- SQL Server monitoring. We'll divide this into reactive and proactive and see how it gets done.
Then we'll look at one of the major efforts for the SQL Server 2005 product—the emergence of Very Large Database (VLDB) management—especially in the area of backup and recovery. Along the way, we'll cover replication, high availability, general data availability, and business intelligence for the database admin.
Before we get to those features, though, we should look at the new tool set, because it is a major shift from Microsoft Management Consoleb(MMC) based tools to Visual Studio. For the database developer and administrator, user interaction and the tool set have many similarities. Hopefully, in the end, this will lead to greater productivity and better-quality database applications.
|At a Glance: What's New for the Database Administrator|
|Microsoft SQL Server 2005 represents the cohesion of the developer and administrator instrumentation. Of all the Microsoft Server products, SQL Server has made the most significant progress related to scalable and extensible database management and authoring tools. SQL Server management tools now include the following:|
The new management tools range from the small, such as creating synonyms for database objects, to the dramatic, such as the introduction of .NET assemblies into the database. What's more, the tools used by DBAs have been completely redesigned and rewritten.
When we look at SQL Server 2005 from a database administration point of view, we can group the features around certain job functions. For example, what features does SQL Server 2005 have for remote management of servers, including setup? What features will allow a DBA to find and mend a blocking process or a poorly configured stored procedure? One of the big challenges that DBAs face is how to keep database systems available as applications and databases constantly change. What about the mundane but important tasks, such as disaster planning, security maintenance, resource allocation, and modeling of future resource needs? How does SQL Server 2005 address these issues?
Additionally, as database products conform more to standards, and the manufacturers copy each other, the question then becomes, "What's innovative?" What has Microsoft delivered in features that will solve a problem you will have tomorrow because Microsoft is thinking ahead? When we look at SQL Server 2005, it's important to separate the features from the marketing message. Sure, Database Snapshot is new and innovative, but is it useful? The release of any product is a combination of reaching for future capabilities—the next big thing—and making the product solve the most common issues, making the product more complete. In the case of Database Snapshot, its usefulness is constrained by its usage scenarios. It's always interesting to hear from customers how they found a new use for a particular technology. Sometimes, these creative usages are the cause of customers' issues. Other times they find legitimate new uses that then influence new features in the next release. This chapter looks at the database management features not as a feature list, but from a DBA task orientation perspective. Before we do that, however, we must look at the center of all the change: SQL Server Management Studio.
SQL Server Management Studio
In SQL Server 7 and 2000, the tools suite was based entirely on MMC. The MMC tool is not designed for real scalability. Customers complained that Enterprise Manager took a long time to open extremely large databases with complex schema. The fact is that Microsoft develops products in a "We'll get there" style. SQL Server Management Studio is one of the few "We've gotten there" tools supplied by Microsoft. Compared to other management tools delivered by Microsoft, SQL Server Management Studio is brilliant. In contrast, you can look at replication; it's still lacking in clear tools strategy. First, know that SQL Server Management Studio is built on the same underpinnings as Visual Studio 2005. Things such as Help and the myriad of panes can really clutter up your screen. On the upside, SQL Server Management Studio includes the following:
- Full support for management of instances of SQL Server 7.0, SQL Server 2000, SQL Server 2005, and Analysis Services 2005. Management Studio dialogs automatically customize to show only the appropriate choices and features, depending on the version of the database server the user is working with. Nonmodal dialogs allow the user to multitask and do more things at once.
- A new integrated Query Editor lets you create queries for all the SQL Server technologies. Additionally, the Query Editor has customization capabilities that make it easier to work with large batch files and complex queries.
- Built-in support for source control. Whether you're using Microsoft SourceSafe or Visual Studio Team System, SQL Server files can be controlled in the same way as other development pieces. You can use any source-control system that uses the Source Safe Control Interface API.
The SQL Server Management Studio implements the SQL Server Management Objects (SMO), which is a new set of managed classes that replace the SQL Server Data Management Objects (SQL-DMO). This major architectural change brings significant enhancements in performance.
SMO's first important optimization over SQL-DMO is delayed instantiation. As you run your application, SMO retrieves objects and properties as needed. You'll notice this right away in the Object Explorer. The key to this optimization is making many small round-trips to the server instead of getting everything up front, as SQL-DMO does and which is overkill in many scenarios. SMO also lets you prefetch entire collections. In addition, you can retrieve objects by using a set of predefined properties. The bottom line is that the programmer has control over SMO behavior, which lets you build an application that suits your needs.
The SMO object model is also cached, meaning that it doesn't propagate object changes to the server immediately. Instead, it caches them until you decide to apply (or discard) the changes. This caching yields fewer round-trips to the server because all changes are sent as one set of batches.
SMO provides advanced scripting functionality as part of the new Scripter object. This object lets you discover database-object dependencies, which results in an object tree. You can create an ordered object list from that tree and then generate a script from the list and optionally specify scripting options (a superset of SQL-DMO's scripting options). This architecture gives you maximum control over each scripting phase, letting you build specialized, customized scripting solutions.
Additionally, SMO includes a script-capture mode that lets you capture the Transact-SQL code that SMO generates when your application performs an operation on an object. For example, a Visual Basic guru can use SMO to grab the Transact-SQL that his or her application generates.
Now that you understand the architectural structure of the how the Management Studio works, let's look at the tools in more detail.
A Connected or Disconnected State
Before you get started with SQL Server Management Studio, you'll notice something radical. The old Enterprise Manager user interface is gone. Moreover, you now have a new connection dialog to work with. The connection dialog allows users to provide both logon credentials and specific connection properties. The connection dialog can connect directly to SQL Server Engine, Analysis Services, Reporting Services, Integration Services, and SQL Server Mobile Edition. The Mobile Edition connection is interesting because the mobile database is often found on a Pocket PC device.
Besides being able to connect to previous versions—meaning SQL Server 2000 and SQL Server 7.0—the connection dialog allows you to decide which database, network method (TCP/IP), named pipes, and shared memory is used to connect. Additionally, you can choose to encrypt your connection and provide specifics such as database, connection time-out, and network packet size.
As soon as you are connected to a database server, you immediately notice the new layout of the windows. As with previous versions, you can view registered servers. You can review the database objects found under the registered server via the new Object Explorer window. It's important to note that you see only objects you have security permissions for.
At the highest level, the database, not the server, is the central container for all the objects found therein. This is a significant departure that makes good sense. First, it's more secure, because the metadata security found in SQL Server 2005 allows for least privileges—all the way down to the database. On another level, having the database as the central axis for all the objects related to the database makes administration easier. When you click the plus symbol next to a database, only those objects directly related are sent back. In previous versions, you had to write queries to get back all the objects related to a database. In large database deployments such as SAP, this new organizational model is a time-saver.
Microsoft strives to not do any take-backs on features between releases. The new SQL Server Management Studio is no exception. I recommend taking the time to get to know the features found in SQL Server 2000 that are renamed and moved in SQL Server 2005. You can still do the following:
- Create a database diagram
- Create database tables via the Visual Database Tools (VDT)
- Create security objects
- Create replication objects such as publications
- Monitor replication
To create a database diagram, you will find a new folder called Database Diagrams under the specific database objects found in the Object Explorer. In Figure 3-1, notice how the database is now the new container for all the subordinate objects. This is a big improvement over previous versions.
Figure 3-1 Object Explorer.