Option 1, Cache-Aside, is correct. The Cache-Aside pattern involves checking the cache for an item before querying the database, allowing efficient cache invalidation in Entity Framework applications.

Option 2, OnQueryExecuted, is correct. This method allows developers to intercept queries after they've been executed, enabling custom caching solutions in Entity Framework.

The InheritanceMapping attribute in Entity Framework is used to specify the base class in a Table-Per-Hierarchy (TPH) inheritance hierarchy. This attribute helps Entity Framework to understand how to map the inheritance hierarchy to the database schema.

Entity Framework manages relationships in a mixed inheritance strategy like TPH with TPT by creating a single table for the base class and separate tables for each derived class. This ensures that the shared properties from the base class are stored only once, avoiding redundancy. Relationships are established using foreign keys, linking the derived class tables to the base class table. This approach allows for efficient querying and navigation of the object graph.

In Entity Framework, the Discriminator column plays a crucial role in implementing inheritance strategies, particularly in Table-Per-Hierarchy (TPH) and Table-Per-Type (TPT) approaches. It stores data type information that distinguishes between different types of entities in the inheritance hierarchy. This information helps Entity Framework to determine the appropriate type when querying polymorphically across the hierarchy, facilitating polymorphic queries.

The main challenge in implementing Table-per-Concrete Class (TPC) inheritance in Entity Framework is dealing with redundancy and potential data inconsistency. Since each concrete class has its own table, duplicate columns may exist across tables, leading to data redundancy and the risk of inconsistency if not properly managed. Ensuring data integrity and maintaining consistency become critical tasks in such scenarios.

In the Code-First approach, Entity Framework handles inheritance by defaulting to Table-Per-Hierarchy (TPH) strategy, where all classes in the inheritance hierarchy are mapped to a single table. To implement Table-Per-Concrete Class (TPC) inheritance, explicit configurations are required, specifying separate tables for each class in the hierarchy, resulting in a challenge due to maintaining relationships and ensuring data integrity across multiple tables.

Entity Framework uses Table-per-Hierarchy (TPH) inheritance by default for mapping inheritance hierarchies. This means that all types in the inheritance hierarchy are mapped to a single table in the database, with a discriminator column used to differentiate between the types. While this approach simplifies the database schema, it may lead to null values and can be less performant when dealing with complex inheritance hierarchies.

Table-per-Type (TPT) inheritance in Entity Framework maps each type in the inheritance hierarchy to its own table in the database. This means the base type and its derived types have separate tables, and the tables are connected through a shared primary key. Unlike TPH, TPT ensures that each type has its own table, which can lead to a more normalized database schema. However, it may result in complex queries due to the need for joins to retrieve data from multiple tables.

Table-per-Hierarchy (TPH) inheritance in Entity Framework maps all derived types in an inheritance hierarchy to a single database table. This means all properties of the derived types are stored in one table, and a discriminator column is used to differentiate between the types. This approach is useful when the derived types share most of their properties and have only a few unique properties. It simplifies the database schema but may lead to null values in the table for properties that are specific to certain derived types.

Joined Tables (JT) strategy would be most suitable. In scenarios requiring polymorphic behavior, Joined Tables allow for efficient querying and maintainability. Each class in the hierarchy maps to its own table, with a one-to-one relationship between the base class table and derived class tables. This strategy ensures database normalization while providing flexibility and clarity in the database structure.

In Entity Framework, Table-Per-Concrete (TPC) can be used to resolve ambiguity in the mapping of a complex model with mixed inheritance.