TAILIEUCHUNG - Hướng dẫn học Microsoft SQL Server 2008 part 54

Về cơ bản, tích hợp đầy đủ Tìm kiếm văn bản (iFTS) SQL Server mở rộng vượt ra ngoài tìm kiếm dữ liệu quan hệ truyền thống bằng cách xây dựng một chỉ số của mỗi từ và cụm từ có ý nghĩa. Ngoài ra, các công cụ tìm kiếm toàn văn cho biết thêm các tính năng tiên tiến như sau: | Part III Beyond Relational 492 so searching for LIKE word is fast but LIKE word is terribly slow. Searching for strings within a string can t use the b-tree structure of an index to perform a fast index seek so it must perform a table scan instead as demonstrated in Figure 19-1. It s like looking for all the instances of Paul in the telephone book. The phone book isn t indexed by first name so each page must be scanned. FIGURE 19-1 Filtering by a where clause value that begins with a wildcard is not sargable that is not a searchable argument so it forces the Query Optimizer to use a full scan. Using Integrated Full-Text Search 19 Basically Integrated Full-Text Search iFTS extends SQL Server beyond the traditional relational data searches by building an index of every significant word and phrase. In addition the full-text search engine adds advanced features such as the following Searching for one word near another word Searching with wildcards Searching for inflectional variations of a word such as run ran running Weighting one word or phrase as more important to the search than another word or phrase Performing fuzzy word phrase searches Searching character data with embedded binary objects stored with SQL Server Using Full-Text Search in the WHERE clause or as a data source like a subquery Full-Text Search must be installed with the instance of SQL Server. If it s not installed on your instance it may be added later using the SQL Server Installation Center see Chapter 4 Installing SQL Server 2008 . What s New with Full-Text Search The history of Full-Text Search began in late 1998 when Microsoft reengineered one of its search engines Site Server Search designed for websites to provide search services for SQL Server 7. The engine was called MSSearch and it also provided search services to Exchange Content Indexing and SharePoint Portal Server 2001. I liked Full-Text Search when it was first introduced back in SQL Server 7 and I m glad that it

• Cơ sở dữ liệu
• Giáo trình SQL Server 2008
• Microsoft SQL Server 2008
• quản trị dữ liệu
• cài đặt SQL Server 2008
• công cụ của SQL Server 2008
• Giáo trình Microsoft SQL Server 2008
• Quản trị cơ sở dữ liệu
• Cài đặt Microsoft SQL Server 2008
• Cấu trúc trình đơn của Microsoft SQL Server 2008
• Cơ sở dữ liệu SQL Server 2008
• Dịch vụ Report trong SQL Server 2008
• SQL Server Business Intelligence Development Studio
• Bảo mật cơ sở dữ liệu SQL Server 2008
• SQL Server 2008
• Cơ bản SQL Server 2008
• Kiến trúc SQL Server 2008
• Phục hồi cơ sở dữ liệu