| OCR Text |
Show and system. Two examples of mechanisms that may be used are files within the file system of a computer, and tables within a relational database management system. Other data storage methodologies may be used as deemed appropriate. The virtual file will be the same type of file that the standard database uses. The mechanism used for the physical file will be a type that is appropriate for the data management system that is used for the physical database. One of the benefits of a virtual database is that data storage methodologies that would not ordinarily be available can be utilized. An existing database that is tied to a particular mainframe hardware and software vendor may be able to implement virtual-database techniques to enable the use of less expensive data storage. For example, a jukebox of optical disks connected to a personal computer may provide increased database storage that is much less expensive than any jukebox that can be connected directly to the mainframe computer. The capacity of the virtual file in a virtual database system is less than the capacity of the physical file. If this were not the case, there would be no need for virtual database technology. The size of the virtual file is determined based on performance considerations. These performance considerations include factors such as the size of a page of data and the number of projected concurrent users. A page of data in a virtual database system is the unit of transfer between the physical and virtual file. This term comes from traditional virtual memory systems. In a traditional virtual memory system, a page of data is a specific size that corresponds to the size 18 |
