Re: [Gnumed-devel] patient search functionality revisited

[Horst Herb]

On Sat, 4 Jan 2003 08:38, Horst Herb wrote:
> > There is also a function levenshtein () which I found useful:
> > it gives the number of substitutions required to match two strings, so
> > is language-agnostic.
>
> problem is that the Levenshtein distance is expensive to calculate. Since
> you cannot even assume that the first letter is spelled correctly (it may
> or may not begin with a silent letter etc), in the worst case you would
> need to traverse the full list of names calculating the distance for each
> single one of them.
>
> Due to the possible number of permutations, it is not practical either to
> have lookup tables for comon cases etc in order to speed up the search.

P.S.: you can try it out yourself; leveshtein is in the postgres contrib 
directory in the "fuzzystrmatch" package

Horst