On Sunday 09 April 2006 13:53, Nadav Har'El wrote: > > Hi all, > ... > > By the way, it is worth repeating the warning that appears everywhere > (including Lucene In Action): while this sort of trick works, RangeQuery > is extremely inefficient (and might not even work) when the number of > different values that are included in the range is very large. > ConstantScoreRangeQuery is better, but also inefficient. My code allows > you to use these queries for floating point values, but in no way makes this > use efficient :-( > > P.S. I wonder if anyone can suggest an alternative implementation for > mantissaFormat() below, which doesn't require a DecimalFormat > object creation. > ... > > /* Our string representation of a floating point number will look as > * follows: > * SEEENN...
One can speed this up by also indexing prefixes as partial numbers in a separate field, for example: S SE SEE SEEEN SEEENN SEEENNN and adapt the numeric range search to use only the shortest ones needed. Iirc using base 3 for the digits N minimizes the number of terms used for a range search in this case, but it's quite a while ago that I did the math for this, and I did not include the exponent digits E at the time... Regards, Paul Elschot --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
