Blocked sort-based indexing (BSBI)

  1. Accumulate records for each block
  2. sort
  3. create the posting lists
  4. write to disk.
  5. merge blocks into 1 sorted order.
def bsbi(docs)
  n = 0
  while not_proceessed(docs):
    n = n + 1
    block = parseNextBlock()
    bsbi_invert(block)
    write_block_to_disk(block, fn)
merge_blocks(f1, ..., fn, fmerged)