For each word wi in the query, an inverted list
is fetched from the index.
Many other researchers , , , , , ,  used ontologies, inverted list
By clustering d-gaps of an inverted list
based on a threshold, and then encoding clustered and non-clustered d-gaps using different methods, we can tailor to the specific properties of different d-gaps and achieve better compression ratio.
Assuming a text collection composed of a large set of documents, an inverted list
is basically composed of a table (the vocabulary) that maintains all the relevant words found in the text, and an associated list for every such word that registers all occurrences of the word in the text (document-id and another information used to rank out responses to users queries) .
For instance, one inverted list
index generated from a customer table might include all the states (AK, AL, AR, etc.
Under QI, for each term x, we collect all the queries that contain it and build an inverted list
In this article we begin by reviewing the principal techniques for evaluation of ranked queries, including: document-ordered or DO processing (also known as document-at-a-time processing, in which the inverted lists
are processed simultaneously); term-ordered or TO processing (also known as term-at-a-time processing, in which each inverted list
is processed in sequence); and some of the more successful optimizations to term-ordered query evaluation, in particular skipping or TOS strategies based on limiting the number of candidate documents considered during query evaluation.
An inverted list
connects all occurrences of a given token despite its position within a group.
We assume that the index is implemented using an inverted list
which, as described in the next section, is composed of a vocabulary (set of terms) and a set of identifiers representing all the documents that contain at least one of the words that are members of the vocabulary.
Since the exact address of the inverted list
is then known, a second access suffices to retrieve the corresponding inverted list
The words in the equivalence class are grouped together by the INQUERY #SYN operator so that at retrieval time INQUERY creates a single inverted list
for the equivalence class by merging the inverted lists
for the words in the class.
Chouvalit and Veera, (2007) Chouvalit Khancome and Veera Boonjing, String Matching using Inverted Lists
, World Academy of Science, Engineering and Technology, 2007