Instead of performing a search against the metadata or a part of the original text represented in a database, a full-text search examines all the words of all the documents stored in the database, and tries to match the search criteria.

A full-text search is able to identify natural-language documents that satisfy a query, and optionally to sort them by relevance to the query. This is often used to retrieve all the documents containing a list of terms.

For a large number of documents, it's not possible to examine all documents for every single query. Thus, we create indexes for specific terms that we might probably use as criteria in our future queries. With these indexes, it's faster to find the documents in which the specified terms are used.

With standard text searches, it's not possible to use indexes in most of the SQL databases, and for every query, the database engine has to scan the whole table. That's why full-text searches are useful, even if it's only...