涵盖查询缓慢1亿+ Doc集合

Question

我非常感谢以下有关查询的任何帮助：

db.searches.find({ $text: { $search: "dragon" }},{product_name:1,_id:0} ).limit(30)

＆＃34;搜索＆＃34;集合有1.26亿个文档，我们的目标是实现亚秒级查询性能。

集合的格式非常简单：

{
"_id" : ObjectId("584b15d12bb299260a000006"),
"product_name" : "This is a product name",
"price" : 876
}

索引和系统配置文件结果都在下面。我们不明白为什么阶段如此缓慢 - 总时间为161秒。同样，不太常见的单词（例如狗）比普通单词（例如龙）快得多，鉴于我们只需要30个文件，这似乎很奇怪。

这是在带有连线虎的MongoDB 3.4.0上运行的。索引应该在内存中，因为它们占用服务器上128GB内存的不到50％。

INDEX

[
{
    "v" : 2,
    "key" : {
        "_id" : 1
    },
    "name" : "_id_",
    "ns" : "marketplaces.searches"
},
{
    "v" : 2,
    "key" : {
        "_fts" : "text",
        "_ftsx" : 1,
        "price" : 1.0
    },
    "name" : "search_index_name_price",
    "ns" : "marketplaces.searches",
    "background" : true,
    "default_language" : "en",
    "language_override" : "en",
    "weights" : {
        "product_name" : 1
    },
    "textIndexVersion" : 3
}
]

系统简介

{
"op" : "query",
"ns" : "marketplaces.searches",
"query" : {
    "find" : "searches",
    "filter" : {
        "$text" : {
            "$search" : "dragon"
        }
    },
    "limit" : 30.0,
    "singleBatch" : false,
    "projection" : {
        "product_name" : 1.0,
        "_id" : 0.0
    }
},
"keysExamined" : 1563505,
"docsExamined" : 1563505,
"cursorExhausted" : true,
"numYield" : 14547,
"locks" : {
    "Global" : {
        "acquireCount" : {
            "r" : NumberLong(29098)
        }
    },
    "Database" : {
        "acquireCount" : {
            "r" : NumberLong(14549)
        }
    },
    "Collection" : {
        "acquireCount" : {
            "r" : NumberLong(14549)
        }
    }
},
"nreturned" : 30,
"responseLength" : 4132,
"protocol" : "op_command",
"millis" : 161315,
"planSummary" : "IXSCAN { _fts: \"text\", _ftsx: 1, price: 1.0 }",
"execStats" : {
    "stage" : "LIMIT",
    "nReturned" : 30,
    "executionTimeMillisEstimate" : 145005,
    "works" : 1563538,
    "advanced" : 30,
    "needTime" : 1563507,
    "needYield" : 0,
    "saveState" : 14547,
    "restoreState" : 14547,
    "isEOF" : 1,
    "invalidates" : 0,
    "limitAmount" : 30,
    "inputStage" : {
        "stage" : "PROJECTION",
        "nReturned" : 30,
        "executionTimeMillisEstimate" : 144635,
        "works" : 1563537,
        "advanced" : 30,
        "needTime" : 1563507,
        "needYield" : 0,
        "saveState" : 14547,
        "restoreState" : 14547,
        "isEOF" : 0,
        "invalidates" : 0,
        "transformBy" : {
            "product_name" : 1.0,
            "_id" : 0.0
        },
        "inputStage" : {
            "stage" : "TEXT",
            "nReturned" : 30,
            "executionTimeMillisEstimate" : 144258,
            "works" : 1563537,
            "advanced" : 30,
            "needTime" : 1563507,
            "needYield" : 0,
            "saveState" : 14547,
            "restoreState" : 14547,
            "isEOF" : 0,
            "invalidates" : 0,
            "indexPrefix" : {},
            "indexName" : "search_index_name_price",
            "parsedTextQuery" : {
                "terms" : [ 
                    "dragon"
                ],
                "negatedTerms" : [],
                "phrases" : [],
                "negatedPhrases" : []
            },
            "textIndexVersion" : 3,
            "inputStage" : {
                "stage" : "TEXT_MATCH",
                "nReturned" : 30,
                "executionTimeMillisEstimate" : 143819,
                "works" : 1563537,
                "advanced" : 30,
                "needTime" : 1563507,
                "needYield" : 0,
                "saveState" : 14547,
                "restoreState" : 14547,
                "isEOF" : 0,
                "invalidates" : 0,
                "docsRejected" : 0,
                "inputStage" : {
                    "stage" : "TEXT_OR",
                    "nReturned" : 30,
                    "executionTimeMillisEstimate" : 143608,
                    "works" : 1563537,
                    "advanced" : 30,
                    "needTime" : 1563507,
                    "needYield" : 0,
                    "saveState" : 14547,
                    "restoreState" : 14547,
                    "isEOF" : 0,
                    "invalidates" : 0,
                    "docsExamined" : 1563505,
                    "inputStage" : {
                        "stage" : "IXSCAN",
                        "nReturned" : 1563505,
                        "executionTimeMillisEstimate" : 20499,
                        "works" : 1563506,
                        "advanced" : 1563505,
                        "needTime" : 0,
                        "needYield" : 0,
                        "saveState" : 14547,
                        "restoreState" : 14547,
                        "isEOF" : 1,
                        "invalidates" : 0,
                        "keyPattern" : {
                            "_fts" : "text",
                            "_ftsx" : 1,
                            "price" : 1.0
                        },
                        "indexName" : "search_index_name_price",
                        "isMultiKey" : true,
                        "isUnique" : false,
                        "isSparse" : false,
                        "isPartial" : false,
                        "indexVersion" : 2,
                        "direction" : "backward",
                        "indexBounds" : {},
                        "keysExamined" : 1563505,
                        "seeks" : 1,
                        "dupsTested" : 1563505,
                        "dupsDropped" : 0,
                        "seenInvalidated" : 0
                    }
                }
            }
        }
    }
},
"ts" : ISODate("2017-04-28T14:34:57.320Z"),
"client" : "127.0.0.1",
"appName" : "MongoDB Shell",
"allUsers" : [],
"user" : ""
}

除非我们能够进一步调整，否则可以考虑使用Elasticsearch。