In SQL, the keyword used for aggregating data in a SELECT statement is SUM. It is used to calculate the sum of values in a particular column, providing a way to aggregate data and obtain meaningful insights from the dataset.

MySQL Workbench facilitates database design by providing a graphical interface. Users can visually create and modify database structures, making it easier to understand and manage the database schema. It also includes tools for running SQL queries, but its primary strength lies in visual design.

Denormalization in conceptual schema design may improve read performance by reducing the need for joins, but it can impact write performance due to increased redundancy. It's a trade-off between read and write efficiency.

A Document Store would be ideal for an e-commerce application with varying product attributes. Document stores allow flexible and dynamic schema design, making it easy to manage diverse product information without a fixed schema.

For a healthcare organization consolidating patient records, a Data Warehouse is more suitable. It allows integration of data from diverse sources while ensuring data privacy and compliance. A Data Warehouse's centralized nature facilitates comprehensive analytics, providing insights across departments while maintaining necessary controls.

In column-family stores, data storage occurs in a column-wise manner. Unlike traditional row-wise storage, where entire rows are stored together, column-family stores organize data by columns. This facilitates efficient retrieval of specific columnar data, making it suitable for scenarios where selective data retrieval is common.

One advantage of using a Key-Value Store is its ability to handle write-intensive workloads efficiently. Key-Value Stores are optimized for simple read and write operations, making them well-suited for scenarios where write operations are frequent and need to be executed quickly.

The SELECT statement in SQL is used to retrieve data from a database. It allows you to specify the columns you want to retrieve and the conditions for selecting specific rows. This statement is fundamental for querying and extracting information from a database.

An Inheritance relationship allows a single entity to inherit properties from multiple superclasses. It is a key concept in object-oriented data modeling, enabling the creation of a more flexible and reusable data model.

In a Star Schema, the fact table is surrounded by Dimension tables. Dimension tables contain descriptive attributes and provide context to the measurements stored in the fact table. This design enhances query performance by simplifying joins and optimizing data retrieval for analytical queries.

Document-based modeling is commonly associated with NoSQL databases. Unlike traditional relational databases, NoSQL databases, especially document stores, allow for the storage and retrieval of unstructured or semi-structured data, making them well-suited for document-based modeling.

A check constraint in a database schema is used to validate data against a specified condition. It ensures that values in a column meet specific criteria, providing a way to control and maintain data integrity.