Patent ID: 9715446
Date: 2017-07-25
CPC Classifications: G06F

Claim:
1. A method for updating an inverted index of a flash solid state disk (SSD), the method comprising: wherein an on-disk inverted index of the flash SSD is constituted by terms and a posting list which is a list of postings corresponding to the respective terms, and at least one block which has a predetermined size and is used for containing postings is provided for each term, and wherein an in-memory inverted index of a memory is constituted by input terms and postings corresponding to the respective input terms, storing postings of an input term that is present in only the in-memory inverted index in a block of an output buffer of the memory and reading out postings of a last block of a posting list of each term to be updated from the on-disk inverted index to thereby storing the read-out postings in a corresponding block of an input buffer of the memory, by scanning the on-disk inverted index and the in-memory inverted index; moving the postings stored in the corresponding block of the input buffer to a corresponding block of the output buffer and attaching new postings of each term in the in-memory inverted index to the corresponding block of the output buffer; and updating the on-disk inverted index by using the postings of each block of the output buffer, wherein in the updating, the blocks of the output buffer to which the new postings are attached are overwritten to the blocks of the on-disk inverted index and the block of the output buffer storing the postings of the input term which is present in only the in-memory inverted index is written in a rear part of the on-disk inverted index.