What method does the ProxySG use to improve the efficiency of web object retrieval?

The method that the ProxySG employs to enhance the efficiency of web object retrieval is pipelining. This technique allows multiple requests to be sent over a network connection before the corresponding responses are received. By using pipelining, the ProxySG can significantly reduce latency, as it minimizes the time spent waiting for individual responses from the server. This is particularly beneficial in scenarios where the user requires access to multiple web objects, such as images or scripts, concurrently. Pipelining ensures that while the first request is being processed, other requests can be sent out, leading to quicker overall data retrieval times and a smoother browsing experience.

This approach stands in contrast to other methods, such as direct download, which focuses on fetching a single object at a time, therefore potentially increasing wait times. Sequential access might involve processing items in a linear fashion, which could also introduce delays. Batch processing typically involves grouping multiple processes together, but it may not provide the same immediate responsiveness for web requests as pipelining does. Thus, the efficiency boost provided by pipelining makes it the most effective method for web object retrieval in this context.