MongoDB functions like Lucene

Hello everybody! Are there similar functions in MongoDB of having Lucene: getTerms () and getTermFrequencies ()?



It might be helpful if you specified exactly what information you're looking for from text search, but there is a way to see what the terms in a text query were with verbose explain:

> db.test.drop()
> db.test.insert({ "t" : "The quick brown fox jumps over the lazy dog" })
> db.test.ensureIndex({ "t" : "text" })
> db.test.count({ "$text" : { "$search" : "jumping quickly" } })
1
> db.test.find({ "$text" : { "$search" : "jumping quickly" } }).explain(true)
{
    "cursor" : "TextCursor",
    "n" : 1,
    "nscannedObjects" : 1,
    "nscanned" : 2,
    "nscannedObjectsAllPlans" : 1,
    "nscannedAllPlans" : 2,
    "scanAndOrder" : false,
    "nYields" : 0,
    "nChunkSkips" : 0,
    "millis" : 0,
    "allPlans" : [
        {
            "cursor" : "TextCursor",
            "n" : 1,
            "nscannedObjects" : 1,
            "nscanned" : 2,
            "scanAndOrder" : false,
            "nChunkSkips" : 0
        }
    ],
    "server" : "luna.local:27017",
    "filterSet" : false,
    "stats" : {
        "type" : "TEXT",
        "works" : 7,
        "yields" : 0,
        "unyields" : 0,
        "invalidates" : 0,
        "advanced" : 1,
        "needTime" : 5,
        "needFetch" : 0,
        "isEOF" : 1,
        "keysExamined" : 2,
        "fetches" : 1,
        "parsedTextQuery" : {
            "terms" : [
                "jump",
                "quick"
            ],
            "negatedTerms" : [ ],
            "phrases" : [ ],
            "negatedPhrases" : [ ]
        },
        "children" : [ ]
    }
}

I don't think there's a way to see the stats on term frequencies for a query or for text indexed fields as of MongoDB 2.6.