9. A computer-implemented system of selecting a content item from a content item database, the system comprising: a content item database which stores a plurality of content items; a server which performs offline processing, the offline processing comprising: accessing a content item from the content item database; creating a first set of tokens from the content item; calculating a first total as a number of tokens in first set of tokens; and storing the first set of tokens and the first total; and a client which performs online processing, the online processing comprising: receiving an incoming query; creating a second set of tokens from the incoming query; calculating a second total as a number of tokens in the second set of tokens; accessing the first set of tokens and the first total corresponding to one of the plurality of content items in the content item database; determining a number of common tokens based on a minimum of a first count and a second count, the first count being a count of each unique token in the first set of tokens and the second count being a count of the each unique token in the second set of tokens; computing a randomized easy signature by: selecting a set of most frequent tokens from the second set of tokens; computing a second total as a number of tokens in the selected set of most frequent tokens; randomly selecting a sub-set of tokens from the selected set of most frequent tokens; determining a number of common tokens based on a minimum of the first count and a third count, the third count being a count of the unique token in the randomly selected sub-set of tokens; and determining the randomized easy signature as a ratio of the number of common tokens and a sum of the first total and the second total; and designating the content item in the content item database as matching the incoming query when the easy signature exceeds a predetermined threshold.
9. A computer-implemented system of selecting a content item from a content item database, the system comprising: a content item database which stores a plurality of content items; a server which performs offline processing, the offline processing comprising: accessing a content item from the content item database; creating a first set of tokens from the content item; calculating a first total as a number of tokens in first set of tokens; and storing the first set of tokens and the first total; and a client which performs online processing, the online processing comprising: receiving an incoming query; creating a second set of tokens from the incoming query; calculating a second total as a number of tokens in the second set of tokens; accessing the first set of tokens and the first total corresponding to one of the plurality of content items in the content item database; determining a number of common tokens based on a minimum of a first count and a second count, the first count being a count of each unique token in the first set of tokens and the second count being a count of the each unique token in the second set of tokens; computing a randomized easy signature by: selecting a set of most frequent tokens from the second set of tokens; computing a second total as a number of tokens in the selected set of most frequent tokens; randomly selecting a sub-set of tokens from the selected set of most frequent tokens; determining a number of common tokens based on a minimum of the first count and a third count, the third count being a count of the unique token in the randomly selected sub-set of tokens; and determining the randomized easy signature as a ratio of the number of common tokens and a sum of the first total and the second total; and designating the content item in the content item database as matching the incoming query when the easy signature exceeds a predetermined threshold. 10. The computer-implemented system of claim 9 , wherein the incoming query comprises at least one of a search string and a user query.