Describe any four disadvantages of the file-based systems (4 Marks)(b) Discuss the five components of the database management system (5 Marks)(c) Identify the roles of the following people(i) Database designer (1 Mark)(ii) Database administrator (1 Mark)(iii) Database user (1 mark)(d) With respect to information management, compare the following concepts;(i) Instance and schema (4 Marks)(ii) Tuple and attribute (4 Marks)(iii) File system and DBMS (4 Marks)(e) There are three default database schemas that found in SQL namely informationschema, mysql and test. Discuss each showing its role in DBMS. (6 Marks)

(a) Four disadvantages of file-based systems are:

1. Data Redundancy: The same data may be duplicated in several files, leading to data redundancy. This not only wastes storage space but also leads to inconsistencies.
2. Data Inconsistency: If data is duplicated and the file is updated, it may lead to inconsistent data.
3. Difficulty in accessing data: File-based systems do not provide powerful query languages, making data retrieval difficult.
4. Lack of security and limited data sharing: File-based systems do not provide sophisticated mechanisms to prevent unauthorized access.

(b) The five components of the Database Management System (DBMS) are:

1. Hardware: This includes the actual computer system, storage devices, and other peripheral devices.
2. Software: This is the actual DBMS software.
3. Data: This is the actual data that is stored in the database.
4. Procedures: These are the instructions and rules that govern the design and use of the database.
5. Database Access Language: This is the language used to interact with the database.

(c) The roles of the following people are:

(i) Database Designer: Responsible for identifying the data to be stored in the database and determining how it will be organized and related. (ii) Database Administrator: Responsible for managing and maintaining the database system, ensuring its performance, security, and availability. (iii) Database User: Interacts with the database to retrieve, update, and manage data.

(d) Comparing the following concepts:

(i) Instance and Schema: An instance is a snapshot of the data in the database at a given point in time while a schema is the overall design or structure of the database. (ii) Tuple and Attribute: A tuple is a row in a table that represents a set of related data. An attribute is a column in a table that represents a certain characteristic of the data. (iii) File System and DBMS: A file system is a method of storing and organizing data on a computer. A DBMS is a software system that uses a standard method of cataloging, retrieving, and running queries on data.

(e) The three default database schemas in SQL are:

1. Information_schema: Provides information about all the other databases. It's a read-only database containing the metadata of the server.
2. Mysql: This schema contains information about the MySQL server including users, privileges, plugins, etc.
3. Test: This is a default schema that can be used for testing purposes. It's usually empty and can be used by users to practice and run test queries.

(a) Four disadvantages of file-based systems are:

1. Data Redundancy and Inconsistency: Since each system uses its own files, the same data may be duplicated in several places leading to data redundancy. This redundancy leads to inconsistency when data is updated in one place but not in others.
2. Difficulty in Accessing Data: Retrieving data from a file system requires writing a new program. This is time-consuming and requires specialized knowledge.
3. Data Isolation: Because data is scattered in various files, it is difficult to obtain a complete view of the data.
4. Integrity Problems: The file-based system lacks the means to enforce integrity constraints. This leads to the possibility of having inconsistent data.

(b) The five components of a Database Management System (DBMS) are:

1. Hardware: This includes the actual computer system, storage devices, and other peripheral devices.
2. Software: This is the actual DBMS software and the operating system.
3. Data: This is the actual data that is stored in the database.
4. Procedures: These are the instructions and rules that govern the design and use of the database.
5. Database Access Language: This is the language used to interact with the database.

(c) The roles of the following people are:

(i) Database Designer: Responsible for identifying the data to be stored in the database and determining how it will be organized and related. (ii) Database Administrator: Responsible for managing the database, ensuring its performance, availability, and security. (iii) Database User: Interacts with the database to perform tasks such as data entry, update, query, and report generation.

(d) Comparing the following concepts:

(i) Instance and Schema: An instance is a snapshot of the data in the database at a given point in time while a schema is the overall design of the database. (ii) Tuple and Attribute: A tuple is a row in a table that represents a set of related data. An attribute is a column in a table that represents a characteristic of the entity. (iii) File System and DBMS: A file system is a method for storing and organizing files while a DBMS is a software system that uses a standard method of cataloging, retrieving, and running queries on data.

(e) The three default database schemas in SQL are:

1. Information Schema: Provides access to database metadata.
2. MySQL: This is the system database that contains information about all other databases.
3. Test: This is a default database where users can perform tests.