Conceptual Data Independence: In this type, the data at the external level must not change due to change in the conceptual level.This type of data independence is relatively easy to achieve and can be seen in most DBMS implementations. Physical Data Independence: This type of data independence is that any change in the location of the database table physically must not affect the database at a conceptual or external level.Each view from the external level is used for a specified set of users and their needs.ĭata Independence in the simplest terms is that the change in data at a certain level in the architecture does not affect data at any other level. External Level: In this level, a view is specified for the database tables seen in the conceptual level.Conceptual level: In this level, the data is represented by a number of database tables which help them be visible at the application level, but the client side is unaware about their locations in the server.Physical Level: At this level in the architecture, the information about the location of the database objects is stored.These parts, though inter-related, are individual modules which can act independently. The DBMS three-tier architecture is divided into three parts. No Backup or Recovery: File system also does not offer and back up or recovery in case the data is corrupted.No Concurrency: Systems using the file system cannot provide access to the same file to multiple users simultaneously.Unauthorized Access: In the file system, anyone can have access to the files, even unauthorized people, which could lead to devastating consequences.Difficult Data Access: In the file system, the user must know the exact location of the file or data to be able to access it whereas, in DBMS, just the relation of the data is enough to find the data.This issue might occur due to typing errors or not updating the information in all copies. Since the file system has multiple copies, this issue could arise quite often. Inconsistency of Data: Inconsistency of data occurs when the data is not the same across all of its available copies. This issue can be frequently seen in the file system. Redundancy of Data: Redundancy of data is when the same data has multiple copies across the database or has data which is outdated despite being updated.User Administration: It can be used for registering, monitoring users, monitoring performance, enforcing data security, dealing with concurrency control, maintaining data integrity, and recovering information corrupted due to unexpected failure.įile system works by storing data on hard disks where they can be modified, created, and deleted as per what their requirement.
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