search engine mainly contain four steps: web scraping, indexing, searching in index db, ordering the search results.
during searching, TERM operator queries inverted list of every emerging word, AND operator converts inverted list into score list and do AND to document id sets in the score list to form a new score list. The score of each document is the product of document id score in all score list
inverted list
access mechanism
- b-tree
- Hash table
Document Manager
Term Dictionary
score list
it records the score of documents that contains the searched word, it varies between 0 and 1
