Trigram search

Consider the string "alice". The trigrams of the string would be "ali", "lic", and "ice", not including spaces. Searching for this string in a database with a trigram-based index would involve finding which objects contain as many of the three trigrams as possible. As a concrete example of using trigram search to search for a regular expression query, consider searching for the string ab[cd]e, where the brackets denote that the third character in the string being searched for could be c or d. In this situation, one could query the index for objects that have the two trigrams abc and bce or the two trigrams abd and bde. Thus, finding this query would involve no string matching, and could just query the index directly, which can be faster in practice. ==See also==