For optimal scalability, Entity Framework can be combined with stored procedures to manage complex query operations. Stored procedures are precompiled SQL queries stored in the database server. They can improve performance by reducing network traffic and database load, especially for complex queries or frequently executed operations. Entity Framework allows developers to execute stored procedures directly, providing flexibility and efficiency in managing complex queries.

The Code-First Approach in Entity Framework allows developers to define the domain model classes first and then generate the database schema from those classes. This strategy offers flexibility and scalability, as it enables easy modification and versioning of the database schema without directly affecting the application's codebase. It's suitable for scenarios where frequent schema changes are expected, promoting better scalability and agility in development.

Explicit Loading in Entity Framework allows developers to explicitly load related entities or collections on demand, reducing the overhead of loading unnecessary data upfront. This technique is beneficial for optimizing performance in scenarios where large data retrieval is causing slow performance. By selectively loading related data when needed, Explicit Loading helps improve application responsiveness and resource utilization, making it an effective optimization strategy for Entity Framework applications dealing with performance issues due to data retrieval.

Implementing Connection Resiliency in an Entity Framework application involves configuring the framework to automatically retry failed database connections, transient errors, or network issues. This approach enhances application robustness and availability, ensuring that the application can gracefully handle sudden spikes in user traffic without experiencing downtime or service disruptions due to connection failures. By resiliently managing database connections, Entity Framework applications can efficiently scale to meet increased demand and maintain a seamless user experience during peak usage periods.

An Entity Type in Entity Framework represents a class that maps to a database table. It defines the structure of the data stored in that table and includes properties that correspond to the table's columns. When working with Entity Framework, developers interact with Entity Types to perform CRUD operations on the underlying database. Understanding Entity Types is fundamental to modeling and querying data effectively in Entity Framework.

Eager loading involves retrieving related data along with the main data in a single query, reducing the number of database trips. This is beneficial for large datasets as it minimizes database round-trips, enhancing performance. Lazy loading, on the other hand, delays the retrieval of related data until it's specifically requested, potentially resulting in numerous individual database calls.

The [StringLength] data annotation is used to specify the maximum length of a string property in an Entity Type in Entity Framework. This allows developers to enforce constraints on string lengths in the database schema.

Complex Types in Entity Framework represent non-entity objects that don't have their own identity and lifecycle. Unlike Entity Types, Complex Types can't be mapped to tables and don't have keys. They are typically used to represent parts of an entity or to encapsulate reusable groups of properties. Understanding the differences between Entity Types and Complex Types is essential for designing efficient and maintainable data models in Entity Framework.

Data Annotations in Entity Framework provide a way to configure entity mapping directly within the model classes using attributes. They allow developers to specify database mappings, define relationships, and set constraints such as primary keys and indexes. While Data Annotations offer a convenient way to configure aspects of the data model, they also provide a means for validating entity properties, making them versatile tools for defining and enforcing data integrity rules in Entity Framework applications.

In Entity Framework, to configure a property as a primary key using Fluent API, you use the PrimaryKey() method. This method allows you to specify the primary key for the entity.