Optimal lucene query options for doing auto completion

Question

I have lucene acting as my data provider for querying a list of countries to do auto completion from a text box which works fine.

My question is in regards what type of query string should I be sending over to get the most expected return results?

Currently I have something along the lines of

var query = string.Format("*{0}*~0.5", txtCountry.Text)

Would there be any recommended tweaks to that for this usage?

Answer 1

Use the spellcheck contrib instead. The query you're doing is very inefficient, since it uses leading wildcards.

If you really don't want to make an n-gram index, then I guess I don't see any real improvements (except obviously increasing the allowable distance will increase the number of results).