The process of normalization involves removing redundancy in a database by organizing data to ensure each piece of information is stored only once. This improves data integrity and reduces the likelihood of anomalies.

In a star schema, the relationship between fact and dimension tables is one-to-many. This means that for each record in the fact table (containing transactional data), there can be multiple related records in the dimension tables (containing descriptive attributes). This structure enables efficient querying and analysis of data in a data warehouse environment.

A Document Store is well-suited for a recommendation engine in a streaming service. It allows storing and retrieving complex user data, such as viewing histories and preferences, in a flexible and scalable manner, enabling efficient analysis for personalized recommendations.

The key difference is that a primary key cannot have null values, ensuring each record is uniquely identified, while a unique key can have null values, allowing for some flexibility in data constraints.

The key distinction lies in the presence of a primary key. A strong entity always has a primary key, while a weak entity relies on a partial key and requires the association with a strong entity for identity. Weak entities lack independence and rely on a strong entity for survival.

A NoSQL database is a type of document-based database optimized for high-speed data retrieval and processing. NoSQL databases are non-relational and provide flexible schema designs, making them suitable for handling unstructured and semi-structured data efficiently.

Data Encryption is not a compression technique. While encryption is essential for securing data, it focuses on converting data into a secure format rather than reducing its size. Common compression techniques like Run-Length Encoding, Huffman Coding, and Lempel-Ziv-Welch aim to minimize data size for storage or transmission purposes.

All of the options are essential steps in performing effective Reverse Engineering. Analyzing existing data, documenting the structure, and interviewing knowledgeable personnel help in understanding and reconstructing the database schema.

Aggregation improves query performance by reducing the amount of data processed. Instead of working with detailed records, aggregating data allows databases to handle summary values, which is more efficient for queries. This optimization becomes crucial, especially in large databases with extensive datasets.

A recursive relationship is one where an entity can be related to itself through a recursive association. This type of relationship is common in scenarios where an entity has a hierarchical or tree-like structure.