On 28/11/2017 18:55, [EMAIL PROTECTED] wrote:
> My question is how is such queries being handled in the library. Is it by looking at the consecutive term positions in documents?

Yes.

> What is the performance impact for such queries?

This depends on how you quantify "performance impact", but in general,
performance should be similar to an ANDQuery of all terms in the phrase.

> Secondly how are they being scored? Is it still tf/idf? If so what is the definition of tf and of idf, for these queries?

It's still tf/idf. For idf, the sum of each term's idf is used. For tf, it's
the number of phrases in a document.

For more details, see PhraseQuery.c and PhraseMatcher.c in core/Lucy/Search.

Nick