SQL được sử dụng để truy cập vào cơ sở dữ liệu từ mã ứng dụng không bao giờ nên được hình thành bằng cách sử dụng nối chuỗi. Các thông số mạnh mẽ đánh máy (thường kết hợp với thủ tục lưu trữ) nên được sử dụng bất cứ nơi nào có thể. Báo cáo chuẩn bị, bộ sưu tập tham số, và các tham số thủ tục lưu trữ nên được sử dụng bất cứ nơi nào có thể. Các ứng dụng đăng nhập nên là một. | 246 Secure replication mechanisms EXEC sp_addlinkedsrvlogin FALCON false NULL sa guardium sp_addlinkedserver FALCON sp_setnetname FALCON EXEC sp_addlinkedsrvlogin FALCON false NULL sa n546jkh and then use the link to request the following data SELECT FROM you will get a completely different set of calls from database A to database B. This is all based on a proprietary RPC protocol that Microsoft uses between databases creating a much more efficient data flow. The RPC calls you would see would be to the following stored procedures sp_getschemalock sp provider types rowset northwind .sp_tables_info_rowset sp_reset_connection sp_releaseschemalock sp_unprepare These calls are within an RPC protocol so it is easy to identify crosslink calls and monitor them. Finally you must remember that even if you have multiple clients connected to database A using the link you will only see a single session going from database A to database B carrying all of these requests. Secure replication mechanisms Replication is the process of copying and maintaining database objects in multiple databases. Replication is used in environments that include distributed databases environments that require high-availability and faulttolerance environments that implement a disaster recovery and or business continuity initiative and much more. Replication is one of the most common advanced features in any database environment and all major platforms support replication even open source databases such as MySQL which included it in version . By definition replication includes the copying of data and or operations from one database environment to another. Many mechanisms are used to Secure replication mechanisms 247 implement replication and you ll see some of these in this section. In all cases the replica database is processing requests that originally come from the master database or that were processed by the master database I use the term .