Abstract: The present disclosure provides a method and a device of hierarchical document filtering. The method includes: selecting multiple documents from a to-be-filtered document set of a current document filtering layer according to a preset sampling strategy, and forming a first document list by using the selected documents according to an order of the selected documents in the to-be-filtered document set; calculating a quality value of each document in the first document list respectively according to a relevance calculation method for the current document filtering layer; reordering the documents in the first document list according to the quality value of each document in the first document list, to obtain a second document list; and filtering the to-be-filtered document set of the current document filtering layer according to the degree of consistency between the first document list and the second document list.

Abstract: In accordance with various embodiments of the disclosed subject matter, a method for fast merging inverted chains, and a related apparatus are provided. In some embodiments, the method comprises: pre-setting an inverted index including a plurality of inverted chains and recording a length of each inverted chain; searching the inverted index and obtaining a subset of the plurality of inverted chains that correspond to at least one keyword; sorting the subset of the plurality of inverted chains in an ascending order of the lengths of the subset of multiple inverted chains; and merging the subset of the plurality of inverted chains sequentially as the ascending order starting from one of the subset of the plurality of inverted chains that has the shortest length.

Abstract: The present disclosure provides a method and a device of hierarchical document filtering. The method includes: selecting multiple documents from a to-be-filtered document set of a current document filtering layer according to a preset sampling strategy, and forming a first document list by using the selected documents according to an order of the selected documents in the to-be-filtered document set; calculating a quality value of each document in the first document list respectively according to a relevance calculation method for the current document filtering layer; reordering the documents in the first document list according to the quality value of each document in the first document list, to obtain a second document list; and filtering the to-be-filtered document set of the current document filtering layer according to the degree of consistency between the first document list and the second document list.

Abstract: In accordance with various embodiments of the disclosed subject matter, a method for fast merging inverted chains, and a related apparatus are provided. In some embodiments, the method comprises: pre-setting an inverted index including a plurality of inverted chains and recording a length of each inverted chain; searching the inverted index and obtaining a subset of the plurality of inverted chains that correspond to at least one keyword; sorting the subset of the plurality of inverted chains in an ascending order of the lengths of the subset of multiple inverted chains; and merging the subset of the plurality of inverted chains sequentially as the ascending order starting from one of the subset of the plurality of inverted chains that has the shortest length.