An absolute necessity of building databases that interact with SQL Server 2000 is using the appropriate database objects to obtain a usable database system while improving response times and maintaining data integrity. There are considerations and trade-offs for choosing one technique over the other. The selection of the most appropriate method to obtain the desired result requires that you know where each technique is best implemented. The exam will test on the appropriate application of each of these objects.
Creating and altering databases involves selecting the physical volume type for each database file, setting the appropriate file properties, placing the objects into the files/filegroups, and ensuring that appropriate adjustments are made as the database matures. The type of business needs that the database is being designed to meet helps to
Try to place onto separate
When you create a database for the first time, that database initially takes most of its attributes from the Model database. The Model database is a system database that SQL Server uses as a kind of template for database creations. It is a good and common practice to set the properties and contents of the Model database based on the majority of new databases that are to be created.
In practice, many objects are stored in the Model database to minimize the need to re-create these objects every time a database is created. Common elements placed in the Model often include specialized
Often an object, such as a user-defined function, standard security role, or corporate information table, can be found in most if not all databases within a company. A property value, such as recovery level, might also have a standard implementation across all servers in the enterprise. If an object or a property value will be present in most of the user databases, placing the object into the Model database or setting a property
All files needed for a database can be created through a single activity using SQL Server's Enterprise Manager (as shown in Figure 3.1) or with a single
Figure 3.1. Database creation from the Enterprise Manager.
SQL Server 2000 enables you to set database files so that they expand and shrink automatically, eliminating the need for additional administration. By default, SQL Server enables data files to increase in size as needed for data storage. Therefore, a file can grow to the point where all disk space is exhausted. You can specify that a file is not to grow beyond its creation size or implement a maximum
CREATE DATABASE MyDatabase ON (NAME = 'DataStore', FILENAME = 'd:\data directory\DataStore_MyDatabase.mdf', SIZE = 1MB, MAXSIZE = 5MB, FILEGROWTH = 1MB) LOG ON (NAME ='LogStore', FILENAME = 'e:\log directory\LogStore_MyDatabase.ldf', SIZE = 1MB, MAXSIZE = 5MB, FILEGROWTH = 1MB)
Following are some important issues with regard to appropriate use of the CREATE DATABASE statement:
In a volatile environment, the database and its
When creating the files, you should set the
parameters so that the database can increase in volume over time. The
configuration should be implemented in larger
You can use the CREATE DATABASE statement to create a database from script. Saving the script enables you to re-create a similar database on another server in the future. Any SQL Server object can have its creation script saved. Using the CREATE DATABASE statement to create a database using multiple files and log files would look similar to this:
CREATE DATABASE Example ON PRIMARY ( NAME = ExampleData, FILENAME = 'c:\mssql\data\sampdat.mdf', SIZE = 10MB, MAXSIZE = 20MB, FILEGROWTH = 2MB), ( NAME = ExampleIndexes, FILENAME = 'c:\mssql\data\sampind2.ndf', SIZE = 10MB, MAXSIZE = 20MB, FILEGROWTH = 2MB), ( NAME = ExampleArchive, FILENAME = 'c:\mssql\data\samparch.ndf', SIZE = 10MB, MAXSIZE = 20MB, FILEGROWTH = 2MB) LOG ON ( NAME = ExampleLog1, FILENAME = 'd:\mssql\log\samplog1.ldf', SIZE = 10MB, MAXSIZE = 20MB, FILEGROWTH = 2MB), ( NAME = ExampleLog2, FILENAME = 'd:\mssql\log\samplog2.ldf', SIZE = 10MB, MAXSIZE = 20MB, FILEGROWTH = 2MB)
When you create the database and its associated files, you provide values to determine the initial file sizes, indicate whether and how the files will grow, and specify some other basic database and file properties. The initial settings are used as a basis for future
Using a Collation Sequence
is a set of rules
In SQL Server 2000 you can specify a nondefault collation for any database on the server. This means that one database does not have to have the same characters or sorting rules as the rest of the databases on the server. If all but one or two of your databases have the same set of characters, a single server can now implement the functionality that previously would have taken two separate machines.
To create a database with a nondefault collating sequence, provide the COLLATE clause on the CREATE DATABASE command. You might also select the collation name from the drop-down box in the Enterprise Manager when you create the database from the GUI.
Collation for an individual column can be different. A collation can be selected for an individual column but is not recommended because it causes great difficulty in the development of front-end applications. Be careful in the use of multiple collating sequences because it makes the transfer and entry of data more complex. It might also limit the application development environment and techniques normally used for data entry and editing.
Be certain of the collation sequence used upon creation of a database. After the collation sequence is set, it can be changed only through rebuilding of the database. If possible, collation decisions should be made during the logical design of the system so that you don't have to rebuild. Although collations can be different, if you want to change the sequence post-creation, you will have to rebuild the database.
Altering Database Properties
Several database properties affect the way in which some SQL Server commands
In altering a database, you can add or remove files and filegroups and/or modify attributes of the files and filegroups. ALTER DATABASE also enables you to set database properties, whereas in previous versions these properties could be changed only using the sp_dboption stored procedure.
After you've set up the options, the