What is the difference between structural dependence and structural independence

In many systems, data independence is an essential function for components of the system. Before we learn Data Independence, a refresher on Database Levels is important. The database has 3 levels as shown in the diagram below.

Consider an Example of a University Database. At the different levels this is how the implementation will look like:. View 2 : studeninfo id:int. Index on the first column of Students.

It allows you to provide a logical description of the database without the need to specify physical structures. Compared to Logical Independence, it is easy to achieve physical data independence. With Physical independence, you can easily change the physical storage structures or devices with an effect on the conceptual schema. Any change done would be absorbed by the mapping between the conceptual and internal levels. Physical data independence is achieved by the presence of the internal level of the database and then the transformation from the conceptual level of the database to the internal level.

Poor data security. Having multiple copies of data increases the chances for a copy of the data to be susceptible to unauthorized access. Data inconsistency. Data inconsistency exists when different and conflicting versions of the same data appear in different places. Reports will yield inconsistent results that depend on which version of the data is used.

Data anomalies. Data redundancy, however, fosters an abnormal condition by forcing field value changes in many different locations. A data anomaly develops when not all of the required changes in the redundant data are made successfully. The data anomalies are commonly defined as follows:. Update anomalies. NoSQL databases do not have a schema in the same rigid way that relational databases have a schema. Each of the four main types of NoSQL database has an underlying structure that is used to store the data.

Data in MongoDB has a flexible schema. Collections do not enforce document structure by default. This flexibility gives you data-modeling choices to match your application and its performance requirements.

Is MongoDB schemaless? As a NoSQL database, MongoDB is considered schemaless because it does not require a rigid, pre-defined schema like a relational database. The applications you use to leverage data stored in MongoDB will enforce a much stricter dynamically typed schema as documents are read from the database.

Begin typing your search term above and press enter to search. Press ESC to cancel. Skip to content Home Social studies What is the structural independence? Social studies. Ben Davis October 17, What is the structural independence?

What is structural independence in a database? Why is data independence important? What is data independence and why is it lacking in file systems provide specific examples?

What is data independence and why it is lacking in file system? What is a characteristic of data independence? What are the types of data independence? What is difference between logical and physical data independence?