To design a caching strategy that queries the database only when there is an update to the Employees table, follow these steps:
* On Table Row Operation: Configure an On Table Row operation to monitor the Employees table for updates.
* Invalidate Cache: When the On Table Row operation detects an update, trigger the invalidate cache operation to clear the cache.
* Object Store Caching Strategy: Use an object-store-caching-strategy to store the cached responses.
* Default Expiration Interval: Use the default expiration interval for the cache, which ensures that cached data is invalidated based on the detection of changes in the Employees table rather than a fixed time interval.
This strategy ensures that the cache is only invalidated when there are actual changes in the Employees table, thereby minimizing redundant transactions and optimizing database performance.
References
* MuleSoft Documentation on Caching Strategies
* Best Practices for Database Integration with MuleSoft

* The Object Store V2 API enables API access to Anypoint Platform Object Store v2.
* You can configure a Mule app to use the Object Store REST API to store and retrieve values from an object store in another Mule app. However, Object Store v2 is not designed for app-to-app communication. To share data between two Mule4 apps, use a queue in Anypoint MQ.
* The Object Store v2 APIs enable you to use REST to perform the following:
- Retrieve a list of object stores and keys associated with an application.
- Store and retrieve key-value pairs in an object store.
- Delete key-value pairs from an object store.
- Retrieve Object Store usage statistics for your organization.
- Object Store provides these APIs:
Object Store API
Object Store Stats API
Reference: https://docs.mulesoft.com/object-store/osv2-apis
Additional Info:
When to use Object Store and when to use VM

During the API implementation phase, the integration team should use the API specification to build the MuleSoft application. This involves leveraging the defined API contract to guide the development of the API' s actual implementation. By adhering to the specification, developers ensure that the API meets the agreed- upon requirements and behaviors. This phase includes coding, integrating with backend systems, and ensuring that the implementation aligns with the design and functional requirements outlined in the API specification.
References:
API-led Connectivity Best Practices
API Lifecycle Management

In this business scenario, the supplier needs to deliver two fundamental integration use cases to provide an end-to-end solution:
A: Synchronized data transfer: This involves ensuring that the customer's purchase orders (sent using ANSI X12 EDI standard) are accurately and timely transferred and reflected in the supplier's ERP system. This synchronization ensures data consistency between the EDI transactions and the ERP system.
B: Sharing data with external partners: This involves providing the customer with a RESTful API to access current product inventory levels from the supplier's ERP system. Sharing data through a RESTful API allows the customer to retrieve up-to-date inventory information as needed.
References:
* EDI Integration with APIs
* Integrating with External Partners Using APIs

As the question says that data needs to be sent across multiple sftp serves , we cannot use non-repeatable streams. The non-repeatable strategy disables repeatable streams, which enables you to read an input stream only once.
You cant use in memory storage because with 0.2 vcore you will get only 1 GB of heap memory. Hence application will error out for file more than 1 GB.
Hence the correct option is file base repeatable stream