An inverted file is a list of sorted words, each one having a set of pointers to the pages where it occurs.
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Advantages
It is the index found in most commercial library systems. The use of an inverted file improves search efficiency by several orders of magnitude. |
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Disadvantages
The need to store a data structure that ranges from 10%–100% or more of the size of the text itself, and a need to update that index as the data set changes.
†State-of-the-art techniques can reduce an inverted file to about 20% of the text.
Some Restrictions
- Only the collection of keywords will be indexed.
- A list of stopwords will not be included in the index.
- A set of rules that decide the beginning of a word or a piece of text that is indexable.
- A list of characters sequences to be indexed (or not indexed).