The Repeater control in ADO.NET allows developers to dynamically generate HTML or other markup for each item in a dataset. This means that the markup can be generated based on the data retrieved from the dataset, providing flexibility in the presentation of the data.

Stored procedures are commonly used in database applications for several reasons. They improve performance by reducing network traffic, as only the name of the stored procedure and any parameters need to be transmitted instead of the full SQL statements. They promote code reuse by encapsulating frequently used logic, reducing redundancy and making maintenance easier. Stored procedures also enhance security by controlling access to database objects and enforcing data integrity rules. Additionally, they can simplify application development by providing a standardized interface to complex business logic.

In LINQ to DataSet, the Where clause is used for filtering data based on specified criteria. It allows you to specify conditions to filter the data and retrieve only the records that match those conditions. For this scenario, using the Where clause enables you to filter sales records based on the product category, thus achieving the desired result.

One technique for improving performance with large datasets is to implement paging, which involves retrieving and displaying a subset of data at a time. This approach reduces the amount of data transferred between the server and client, leading to faster page load times and improved responsiveness. Additionally, using efficient data retrieval methods such as stored procedures or indexed queries can help minimize database load and improve overall performance. Caching frequently accessed data and optimizing data binding operations can also contribute to better performance when working with Repeater and DataList controls.

The correct option is "Code-First." Code-First is a feature of Entity Framework that allows developers to define the domain model classes first, and then generate the database schema based on those classes. This approach provides flexibility and control over the database design while working primarily with object-oriented code.

ADO.NET allows developers to create custom data providers to support various databases, including NoSQL databases like MongoDB. Custom providers can extend ADO.NET's functionality to work with different data storage systems.

Object-Relational Mapping (ORM)

LINQ (Language Integrated Query) enables developers to query and manipulate collections, databases, XML documents, and any data source that can be queried with LINQ. It's a versatile tool for working with different types of data sources, making it easier to write expressive and powerful queries in C# and other .NET languages.

In LINQ to Entities, the "Include" method is used to specify navigation properties to be eagerly loaded. Navigation properties are properties on an entity that allow you to navigate to related entities.

The SaveChanges method in Entity Framework is used to persist all pending changes made to entity objects in the context to the underlying database. This includes inserting new records, updating existing ones, and deleting entities as necessary. By calling SaveChanges, the framework ensures that any modifications made within the context are correctly synchronized with the database, maintaining data consistency. This method is essential when updating data as it commits the changes made by the application, making them permanent in the database.

Utilizing SqlDataReader's Forward-Only Cursor mode provides the most efficient way to read a large dataset from a database. This mode allows for a single-pass read-through of the data, reducing the overhead associated with maintaining a scrollable cursor or performing asynchronous operations. Scrollable cursors, UpdateBatchSize property, and ExecuteReaderAsync method might introduce unnecessary overhead or complexity in scenarios where a simple, efficient read-through is sufficient.

LINQ stands for Language Integrated Query. It is a Microsoft .NET Framework component that adds native data querying capabilities to .NET languages. It allows developers to query different types of data sources in a uniform way.