Scoring documents in Lucene 6.2.0 - lucene

Question

My query in lucene 6.2.0 goes like:
query query = new PhraseQuery.Builder()
.add(new Term("country","russia"))
.setSlop(1)
.build();
Basically among all my documents which are:
{
"_id" : ObjectId("586b723b4b9a835db416fa26"),
"name" : "test",
"countries" : {
"country" : [
{
"name" : "russia"
},
{
"name" : "USA china"
}
]
}
}
{
"_id" : ObjectId("586b73f24b9a835fefb10ca5"),
"name" : "nitika jain",
"countries" : {
"country" : [
{
"name" : "russia and denmrk"
},
{
"name" : "USA china"
}
]
}
}
{
"_id" : ObjectId("586b744f4b9a835fefb10ca7"),
"name" : "arjun",
"countries" : {
"country" : [
{
"name" : "russia pakistan"
},
{
"name" : "india iraq"
}
]
}
}
I want a document which has only russia. Ideally it should be the one highest scored, but instead I get something like "Found 3 hits."
Document<stored,indexed,tokenized<id:586b723b4b9a835db416fa26> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<name:test> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<countries:{ "country" : [ { "name" : "russia"} , { "name" : "USA china"}]}> stored,indexed,tokenized<country:russia> stored,indexed,tokenized<country:USA china>>**0.12874341**
Document<stored,indexed,tokenized<id:586b73f24b9a835fefb10ca5> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<name:nitika jain> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<countries:{ "country" : [ { "name" : "russia and denmrk"} , { "name" : "USA china"}]}> stored,indexed,tokenized<country:russia and denmrk> stored,indexed,tokenized<country:USA china>>**0.12874341**
Document<stored,indexed,tokenized<id:586b744f4b9a835fefb10ca7> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<name:arjun> stored,indexed,tokenized,omitNorms,indexOptions=DOCS<countries:{ "country" : [ { "name" : "russia pakistan"} , { "name" : "india iraq"}]}> stored,indexed,tokenized<country:russia pakistan> stored,indexed,tokenized<country:india iraq>>**0.12874341**
All 3 results are equally scored. How can I get the document with only russia to be highest scored?

Answer 1

In Phrase queries, the slop is zero by default, requiring exact matches. that means that if you modify your query in this way:
query query = new PhraseQuery.Builder()
.add(new Term("country","russia"))
.build();
you'll get what you're looking for.