To resolve bean overriding issues and ensure that the intended beans are registered, you can use the @Primary annotation on the bean definition of the intended bean. This annotation marks the bean as the primary candidate for injection when there are conflicts, ensuring that it's selected over others. It's a common way to resolve unintentional bean overriding in Spring Boot applications.

You can create a custom Auto Configuration in Spring Boot by adding a custom class to the "org.springframework.boot.autoconfigure" package and annotating it with @Configuration and @EnableAutoConfiguration. This class should include the necessary configurations for your custom behavior. Modifying Spring Boot core code is not recommended and should be avoided.

To handle cache concurrency in Spring Boot, you can use the @Cacheable annotation with a sync attribute set to true. This ensures that cacheable methods are synchronized, preventing multiple threads from recomputing the same cached value concurrently. The other options are not standard approaches to handling cache concurrency in Spring Boot, and using a ConcurrentCacheManager is not a built-in feature of Spring Boot's caching framework.

The @ControllerAdvice annotation in a Spring Boot application is used to handle exceptions at the controller level. It allows you to define global exception handling logic that can be applied across multiple controllers. This is particularly useful for defining consistent error handling behavior in your application. The other options do not accurately describe the role of @ControllerAdvice.

In Spring Boot's reactive programming, the Mono interface represents a stream of 0 or 1 item. It's part of Project Reactor, which is used for reactive programming in Spring. A Mono can emit either a single item or no item at all, making it suitable for situations where you expect zero or one result, such as fetching a single record from a database or handling optional values.

The primary annotation used to declare a field to be validated using JSR-303 Bean Validation is @NotNull. This annotation specifies that a field must not be null, and it is commonly used to validate input parameters or form fields to ensure they have values. The other annotations mentioned have different purposes and are not typically used for field validation.

To resolve ambiguity when there are multiple beans of the same type, the "@Qualifier" annotation in Spring is used. It allows you to specify which bean should be wired by providing the name or ID of the desired bean. The other annotations, such as "@Component," "@Service," and "@Repository," are used for different purposes, like marking classes for component scanning, but they do not resolve bean wiring ambiguity.

Spring Boot, using the @TestContainers annotation, allows you to create disposable instances of databases, web browsers, or other services in Docker containers for testing purposes. It simplifies the process of setting up and tearing down these resources for testing.

Database query optimization involves techniques such as indexing, query rewriting, and efficient database design. It aims to reduce the number of queries and improve their execution plans, resulting in faster response times and reduced resource consumption. In a Spring Boot application, well-optimized queries are crucial for efficient data retrieval and manipulation. Improperly optimized queries can lead to performance bottlenecks and increased response times.

To bind the properties defined in the YAML file to a Java object in Spring Boot, you can use the @ConfigurationProperties annotation. This annotation allows you to map YAML or properties file values to fields in a Java object, making it a powerful tool for handling configuration in Spring Boot applications.