Essential Concepts in Database Management Systems (DBMS)
Database Administrator (DBA) Functions
A Database Administrator (DBA) is responsible for managing and maintaining the database system. Key functions include:
- Ensuring data security.
- Creating and managing user accounts.
- Managing storage allocation.
- Performing backups and recovery procedures.
- Tuning database performance.
- Maintaining database integrity.
Specialization and Aggregation in ER Modeling
Specialization is the process of dividing an entity into sub-entities based on specific characteristics (e.g.,
Read MoreDatabase Architecture, Data Models, and Relational Algebra
**i) View of Data:**A database has multiple views to cater to different users.It consists of 3 levels:*Internal Level (Physical View):*Defines how data is physically stored on hardware.*Conceptual Level (Logical View):*Represents the entire database structure without storage details.*External Level (User View):*Provides customized views of data for different users,hiding unnecessary details.**ii) Data Abstraction:**Data abstraction simplifies database complexity by hiding lower-
level details.It 
Essential Database and Data Management Concepts
Database Fundamentals
Core Database Terminology
- Catalog: A set of schemas that constitute the description of a database.
- Schema: The structure that contains descriptions of objects created by a user (base tables, views, constraints).
- Data Definition Language (DDL): Commands that define a database, including creating, altering, and dropping tables and establishing constraints.
- Data Manipulation Language (DML): Commands that maintain and query a database.
- Data Control Language (DCL): Commands that control
Database Keys: Super, Candidate, Primary & 3NF Concepts
Super Key vs. Candidate Key Differences
Understanding the distinctions between Super Keys and Candidate Keys is crucial in database design. Below are their key characteristics:
Super Key Characteristics
- A Super Key is an attribute (or set of attributes) used to uniquely identify all attributes in a relation.
- Not all Super Keys can be Candidate Keys.
- The collection of Super Keys helps establish the criteria for selecting Candidate Keys.
- In a relation, the number of Super Keys is typically greater than
SQL and Relational Database Concepts Assessment
SQL and Database Concepts Questions
- 
Which of the following will fix one of the issues with the SQL statement in Figure 1a?- StudentID, CRN AUTO_INCREMENT PRIMARY KEY
- PRIMARY KEY (StudentID)
- FOREIGN KEY (StudentNum) REFERENCES Housing (DormNum)
- (StudentID) AUTO_INCREMENT PRIMARY KEY
- DELETE TABLE Students
 
- 
Which of the following is true about Figure 3?- The tables have too many primary keys (PKs)
- It uses Chen’s notation
- It uses SQL, not ANSI
- It uses Crow’s Foot notation
- It is a Database Management System (DBMS)
 
Database Partitioning: Principles, Methods, and Features
Database Partitioning Principles
Completeness: Every piece of data in the original table must appear in at least one partition.
Why? This ensures no data is lost during the partitioning process.
Example: If a Customers table is partitioned into regions, all customers must belong to one of the regional partitions.
Reconstruction: It must be possible to reconstruct the original table by combining the partitions.
Why? This ensures that partitioning doesn’t make it impossible to retrieve the full dataset
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