1. A method for discovering frequently accessed subtrees, performed by an electronic apparatus, comprising: receiving a request from a source; acquiring a global prefix tree (GPT) comprising a plurality of traversal paths, each traversal path representing one of a plurality of frequently accessed subtrees; and transmitting a response comprising the GPT to the source, thereby enabling the source to discover the frequently accessed subtrees based on the GPT, wherein the GPT is generated in response to a plurality of data streams respectively comprising accessed nodes of a partially traversed theoretical tree.