Database II - SS3 ICT Past Questions and Answers - page 2

Database normalization is a process in database design that involves organizing data in a way that reduces redundancy and data anomalies (such as update anomalies, insert anomalies, and delete anomalies). The main goal is to structure the database schema to minimize data duplication and ensure data integrity. This is achieved by dividing tables into smaller, related tables and establishing relationships between them using primary keys and foreign keys. The normalization process is typically divided into several normal forms, such as First Normal Form (1NF), Second Normal Form (2NF), and so on, with each level addressing specific types of data redundancy and dependency issues.

Determine the Table's Purpose: Define what the table will store, its columns, and the type of data it will hold.

Choose a Suitable Data Type: Specify the data type for each column (e.g., text, integer, date).

Define Constraints: Set constraints like primary keys, unique constraints, and foreign keys to ensure data integrity.

Write the SQL Statement: Use SQL (Structured Query Language) to create the table, specifying column names, data types, and constraints.

Execute the SQL Statement: Run the SQL command to create the table within the database.

Verify the Table: Check that the table has been created correctly by examining its structure.

Indexing: Create indexes on columns frequently used in queries to speed up data retrieval.

Optimizing Queries: Write efficient SQL queries that use appropriate joins and filtering conditions.

Database Design: Ensure a well-structured database schema with normalized tables to reduce redundant data.

Caching: Use caching mechanisms to store frequently accessed query results in memory.

Hardware Upgrades: Improve server hardware, such as increasing RAM or using faster storage devices.

Load Balancing: Distribute database load across multiple servers using load balancing techniques.

Partitioning: Partition large tables to divide data into more manageable segments.

Regular database backups are essential for data protection and recovery in case of data loss due to various reasons like hardware failures, data corruption, or human errors. Backups serve as a snapshot of the database at a specific point in time.

To restore a database from a backup:

Identify the backup source, whether it's a full backup, incremental backup, or differential backup.

Ensure that the database server is in the correct state for restoration.

Use the appropriate command or tool provided by the DBMS to restore the backup, specifying the backup file or location.

Follow any additional instructions related to log files or transaction logs, depending on the type of backup.

Verify the restored database to ensure data integrity and consistency.

The specific steps and commands can vary depending on the database management system being used.