tailieunhanh - Beginning SQL Server 2008 for Developers From Novice to Professional phần 6

nói rằng bạn có một khách hàng sở hữu sản phẩm ngân hàng. Một hạn chế tham chiếu sẽ ngăn chặn hồ sơ của khách hàng bị xóa trong khi những sản phẩm tồn tại. SQL Server không tự động tạo ra các chỉ số trên các phím nước ngoài của bạn. Tuy nhiên, như là chìa khóa giá trị cột nước ngoài cần phải được xác định bởi SQL Server khi gia nhập bảng cha, nó là hầu như luôn luôn được đề nghị một chỉ số được tạo ra trên các cột của phím nước ngoài | 200 CHAPTER 7 DATABASE BACKUPS RECOVERY AND MAINTENANCE 3. After execution you should see output similar to the following where the transaction log has been successfully backed up and placed on file 4 100 percent processed. Processed 4 pages for database ApressFinancial file ApressFinancial_log on file 4. BACKUP LOG successfully processed 4 pages in seconds MB sec . Restoring a Database N ow that the data has been backed up what if you need to complete a restore As has been mentioned there are two scenarios where a restore could be required from a backup or when a media failure occurs. The second type of restore is not one you wish to perform but you could set it up by creating a long-running transaction and then simply switching your computer off not one of life s greatest ideas to do deliberately This book therefore will not be demonstrating this option and it is not really for a beginner to attempt. However I will discuss the concept within this section of the chapter. The first option a simple restore is easy to replicate and perform and this will be the option we will be looking at. You can choose between two means to restore the database SQL Server Management Studio and T-SQL. This is a scenario that you hope you will never perform in a production environment but it will happen. If you just need a restore within the development environment to remove test data and get back to a stable predefined set of data to complete the testing then this next section should help you. It might also be that you do a weekly refresh of your user test region from a production backup. Before completing the restore let s first modify the ApressFinancial database to prove that the restore works as there is no data within the database yet to prove the restore has worked by that method. Keep in mind however that a restore will restore not only the data structures but also the data the permissions and other areas of the database not yet covered in the book for example .