Method for updating inverted index of flash ssd

A method for updating an inverted index of a flash solid state disk (SSD),

• wherein an on-disk inverted index 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 the postings is provided in each term, and
• an in-memory inverted index is constituted by input terms and postings corresponding to the respective terms, the method comprising:
• storing postings of a term that is present in only the in-memory inverted index in a block of the output buffer and reading postings of a last block of each posting list to be updated from the on-disk inverted index to be stored in each block of the input buffer, by scanning the on-disk inverted index and the in-memory inverted index;
• moving postings of the input buffer to the blocks of the output buffer for each block and attaching new postings of the in-memory inverted index to the block corresponding to the output buffer;
• and
• updating the on-disk inverted index by using the postings of each block of the output buffer.