Do you know something about the Schema in the database management system and how it works and the database? Here we are going to discuss the different types of Schema in the database and what are the different layers they are using in different kinds of data warehousing systems.
Do you know schema is highly related to the Database Management System? So, let's begin with the first and the foremost question of this article: what is Schema? In a very simple word, the design of a database is referred to as schema.
When the database is entirely described by a schema, then it is known as the database schema. In addition to this, it has segregated into three different parts such as physical Schema, logical schema, and view schema. We are going to discuss all three in detail below. These are also known as three levels of data abstraction.
First of all, we will begin with a physical schema which is a kind of design of a database at a physical layer. Further, it also indicates how the data is stored in a different slab of storage. In this type of schema, there is no need for any kind of Pros programmers or database administrators as it includes only physical blocks of storage in the database.
Let us move forward to the next schema. Here, we have a logical schema of the database at a logical level and it requires the programmers as well as database administrators who have to work on these data structures according to the logic. At this level of logical schema, a definite type of data records is contained in the data that can be stored as data structures. On the other hand, the internal details like the implementation of data structure will remain hidden at this level as similar to that of a physical schema.
The last one is the View Schema, which is defined as the design of a database which is appeared at the level of end-user. Thus, it is the final interaction between the database systems and the end-users.
Now we are going to explain the three scammers with the help of an example which will clear the concept in brief. Let us start with the example.
To exemplify, take an example of student information that needs to be stored on a student table. At the physical level, these records are distributed as a block of storage in bytes, gigabytes, terabytes and can be higher in memory. All these elements remain hidden from the programmers as there is no need for these professionals at this level. When we are done with physical schema, then it comes to the logical level where these student records can be properly illustrated according to the data types and managed as fields and attributes and also, logically implemented according to their relationship with each other. Now, come to the last level which is view schema. Here, the user can interact with the system and just enter all the details as required by the system. The user does not have any knowledge about the data storage and how it is stored and what features are still hidden.