Slayt 1

1
An obvious way to implement the Boolean search is
through the inverted file. We store a list for
each keyword in the vocabulary, and in each list
put the addresses (or numbers) of the documents
containing that particular word. Suppose that
The keyword CAT indexes D1 (Document 1), D2,
D3, D4 DOG indexes D1, D2 COLLAR indexes D1,
D2, D3 and LEASH indexes D1. Create an
inverted file for these four keywords and four
documents.
2
Keyword/Document Document 1 Document 2 Document 3 Document 4
CAT
DOG
COLLAR
LEASH
3
Create inverted file
Sort inverted file
4
Postings file
Dictionary file
5
OR
6
LEASH
DOG
CAT
COLLAR