10. A system for reducing a set of strings to approximately match to a first string by determining an edit distance between the first string and the set of strings is within a predetermined threshold, the system comprising: a device receiving a request to approximately match a first string with a set of strings using a predetermined edit distance; an approximate matching engine executing on a processor of the device, generating a difference histogram comprising a distribution of a difference in a first number of occurrences of each character of a character set in the first string of the request and a second number of occurrences of each character of the character set in a second string of the set of strings, by incrementing each cell in the difference histogram corresponding to each character in the first string by a positive value and decrementing each cell in the difference histogram corresponding to each character set in the second string by a negative value; and and wherein the approximate matching engine identifies the second string as having an edit distance from the first string greater than the predetermined edit distance in response to determining that a first sum of values across a plurality of cells of the difference histogram is greater than a predetermined threshold and that a second sum of negative values across a second plurality of cells of the difference histogram is less than a negative of the predetermined threshold.
18. The system of claim 10 , wherein one of the predetermined edit distance or the predetermined threshold is set based on a percentage of number of characters of the first string.