On Thu, Nov 20, 2014 at 1:30 PM, Peter Geoghegan <pg@heroku.com> wrote:
> I mean the suggestion of raising the cost threshold more gradually,
> not as a step function of the number of characters in the string [1]
> where it's either over 6 characters and must pass the 50% test, or
> isn't and has no absolute quality test. The exact modification I
> described will FWIW remove the "quantity" for "qty" suggestion, as
> well as all the similar suggestions that you found objectionable (like
> "tit" also offering a suggestion of "quantity").
>
> If you look at the regression tests, none of the sensible suggestions
> are lost (some would be by an across the board 50% absolute quality
> threshold, as I previously pointed out [2]), but all the bad ones are.
> I attach failed regression test output showing the difference between
> the previous expected values, and actual values with that small
> modification - it looks like most or all bad cases are now fixed.
That does seem to give better results, but it still seems awfully
complicated. If we just used Levenshtein with all-default cost
factors and a distance cap equal to Max(strlen(what_user_typed),
strlen(candidate_match), 3), what cases that you think are important
would be harmed?
--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company
