MongoDB在排序时在组件索引中滥用地理空间索引_Mongodb_Mongodb Query_Multi Index

MongoDB在排序时在组件索引中滥用地理空间索引

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MongoDB在排序时在组件索引中滥用地理空间索引,mongodb,mongodb-query,multi-index,Mongodb,Mongodb Query,Multi Index,我转到Mongo命令行（版本4.4.1）并执行以下操作结果表明，虽然查询（按位置查找和按类别排序）有一个完美的匹配，但没有使用索引（位置，类别2）。获奖计划显示使用了类别1索引： “索引名称”：“位置、范围、类别1” db.places.find({ location: { $near: { $geometry: { type: "Point", coordinates: [ 0, 0 ] } } } }).sort({ category2 : 1 }).explai

我转到Mongo命令行（版本4.4.1）并执行以下操作

结果表明，虽然查询（按位置查找和按类别排序）有一个完美的匹配，但没有使用索引（位置，类别2）。获奖计划显示使用了类别1索引： “索引名称”：“位置、范围、类别1”

 db.places.find({ location: { $near: { $geometry: { type: "Point", coordinates: [ 0, 0 ] } } } }).sort({ category2  : 1 }).explain()
{
    "queryPlanner" : {
        "plannerVersion" : 1,
        "namespace" : "dev.places",
        "indexFilterSet" : false,
        "parsedQuery" : {
            "location" : {
                "$near" : {
                    "$geometry" : {
                        "type" : "Point",
                        "coordinates" : [
                            0,
                            0
                        ]
                    }
                }
            }
        },
        "queryHash" : "8766F2A3",
        "planCacheKey" : "9B5661A5",
        "winningPlan" : {
            "stage" : "SORT",
            "sortPattern" : {
                "category2" : 1
            },
            "memLimit" : 104857600,
            "type" : "simple",
            "inputStage" : {
                "stage" : "GEO_NEAR_2DSPHERE",
                "keyPattern" : {
                    "location" : "2dsphere",
                    "category1" : 1
                },
                "indexName" : "location_2dsphere_category1_1",
                "indexVersion" : 2,
                "inputStage" : {
                    "stage" : "FETCH",
                    "inputStage" : {
                        "stage" : "IXSCAN",
                        "keyPattern" : {
                            "location" : "2dsphere",
                            "category1" : 1
                        },
                        "indexName" : "location_2dsphere_category1_1",
                        "isMultiKey" : false,
                        "multiKeyPaths" : {
                            "location" : [ ],
                            "category1" : [ ]
                        },
                        "isUnique" : false,
                        "isSparse" : false,
                        "isPartial" : false,
                        "indexVersion" : 2,
                        "direction" : "forward",
                        "indexBounds" : {
                            "location" : [
                                "[-9223372036854775807, -6917529027641081857]",
                                "[-6917529027641081855, -4611686018427387905]",
                                "[1, 2305843009213693951]",
                                "[2305843009213693953, 4611686018427387903]",
                                "[4611686018427387905, 6917529027641081855]",
                                "[6917529027641081857, 9223372036854775807]"
                            ],
                            "category1" : [
                                "[MinKey, MaxKey]"
                            ]
                        }
                    }
                }
            }
        },
        "rejectedPlans" : [
            {
                "stage" : "SORT",
                "sortPattern" : {
                    "category2" : 1
                },
                "memLimit" : 104857600,
                "type" : "simple",
                "inputStage" : {
                    "stage" : "GEO_NEAR_2DSPHERE",
                    "keyPattern" : {
                        "location" : "2dsphere",
                        "category2" : 1
                    },
                    "indexName" : "location_2dsphere_category2_1",
                    "indexVersion" : 2,
                    "inputStage" : {
                        "stage" : "FETCH",
                        "inputStage" : {
                            "stage" : "IXSCAN",
                            "keyPattern" : {
                                "location" : "2dsphere",
                                "category2" : 1
                            },
                            "indexName" : "location_2dsphere_category2_1",
                            "isMultiKey" : false,
                            "multiKeyPaths" : {
                                "location" : [ ],
                                "category2" : [ ]
                            },
                            "isUnique" : false,
                            "isSparse" : false,
                            "isPartial" : false,
                            "indexVersion" : 2,
                            "direction" : "forward",
                            "indexBounds" : {
                                "location" : [
                                    "[-9223372036854775807, -6917529027641081857]",
                                    "[-6917529027641081855, -4611686018427387905]",
                                    "[1, 2305843009213693951]",
                                    "[2305843009213693953, 4611686018427387903]",
                                    "[4611686018427387905, 6917529027641081855]",
                                    "[6917529027641081857, 9223372036854775807]"
                                ],
                                "category2" : [
                                    "[MinKey, MaxKey]"
                                ]
                            }
                        }
                    }
                }
            }
        ]
    },
    "serverInfo" : {
        "host" : "XXXX",
        "port" : 27017,
        "version" : "4.4.1",
        "gitVersion" : "ad91a93a5a31e175f5cbf8c69561e788bbc55ce1"
    },
    "ok" : 1
}

“获胜计划”：{ “阶段”：“排序”， “排序模式”：{ “类别2”：1 }, “memLimit”：104857600， “类型”：“简单”， “输入阶段”：{ “舞台”：“地球仪近球”， “按键模式”：{ “位置”：“2dsphere”， “类别1”：1 }, “indexName”：“位置、范围和类别”，参见

db.places.find({ location: { $near: { $geometry: { type: "Point", coordinates: [ 0, 0 ] } } } }).sort({ category2 : 1 }).explain() { "queryPlanner" : { "plannerVersion" : 1, "namespace" : "dev.places", "indexFilterSet" : false, "parsedQuery" : { "location" : { "$near" : { "$geometry" : { "type" : "Point", "coordinates" : [ 0, 0 ] } } } }, "queryHash" : "8766F2A3", "planCacheKey" : "9B5661A5", "winningPlan" : { "stage" : "SORT", "sortPattern" : { "category2" : 1 }, "memLimit" : 104857600, "type" : "simple", "inputStage" : { "stage" : "GEO_NEAR_2DSPHERE", "keyPattern" : { "location" : "2dsphere", "category1" : 1 }, "indexName" : "location_2dsphere_category1_1", "indexVersion" : 2, "inputStage" : { "stage" : "FETCH", "inputStage" : { "stage" : "IXSCAN", "keyPattern" : { "location" : "2dsphere", "category1" : 1 }, "indexName" : "location_2dsphere_category1_1", "isMultiKey" : false, "multiKeyPaths" : { "location" : [ ], "category1" : [ ] }, "isUnique" : false, "isSparse" : false, "isPartial" : false, "indexVersion" : 2, "direction" : "forward", "indexBounds" : { "location" : [ "[-9223372036854775807, -6917529027641081857]", "[-6917529027641081855, -4611686018427387905]", "[1, 2305843009213693951]", "[2305843009213693953, 4611686018427387903]", "[4611686018427387905, 6917529027641081855]", "[6917529027641081857, 9223372036854775807]" ], "category1" : [ "[MinKey, MaxKey]" ] } } } } }, "rejectedPlans" : [ { "stage" : "SORT", "sortPattern" : { "category2" : 1 }, "memLimit" : 104857600, "type" : "simple", "inputStage" : { "stage" : "GEO_NEAR_2DSPHERE", "keyPattern" : { "location" : "2dsphere", "category2" : 1 }, "indexName" : "location_2dsphere_category2_1", "indexVersion" : 2, "inputStage" : { "stage" : "FETCH", "inputStage" : { "stage" : "IXSCAN", "keyPattern" : { "location" : "2dsphere", "category2" : 1 }, "indexName" : "location_2dsphere_category2_1", "isMultiKey" : false, "multiKeyPaths" : { "location" : [ ], "category2" : [ ] }, "isUnique" : false, "isSparse" : false, "isPartial" : false, "indexVersion" : 2, "direction" : "forward", "indexBounds" : { "location" : [ "[-9223372036854775807, -6917529027641081857]", "[-6917529027641081855, -4611686018427387905]", "[1, 2305843009213693951]", "[2305843009213693953, 4611686018427387903]", "[4611686018427387905, 6917529027641081855]", "[6917529027641081857, 9223372036854775807]" ], "category2" : [ "[MinKey, MaxKey]" ] } } } } } ] }, "serverInfo" : { "host" : "XXXX", "port" : 27017, "version" : "4.4.1", "gitVersion" : "ad91a93a5a31e175f5cbf8c69561e788bbc55ce1" }, "ok" : 1 }
$near是一个范围查询，索引必须在具有范围条件的字段之前引用正在排序的字段，以满足范围和排序要求
这两个索引都不能用于对查询进行排序。MongoDB选择第一个索引，因为它们的可用部分只是地理索引

由于您没有使用$near指定距离，您可能正在通过索引扫描获取设置了位置字段的所有文档。
那么我该怎么做呢？我只需要按位置查找并按类别2排序。我尝试了另一种方法创建索引，例如
db.places.createIndex（{category2:1，位置：“2dsphere”}
，但随后我得到了错误NoQueryExecutionPlans完整的错误是：``错误：解释失败：{“ok”：0，“errmsg”：“错误处理查询：ns=dev.placesTree:GEONEAR field=location maxdist=1.79769e+308 isNearSphere=0\nsert:{category2:1.0}\nProj:{}”\n planner返回错误：：原因：：无法找到$geoNear查询的索引，“代码”：291，“代码名”：“NoQueryExecutionPlans”}：``此外，如果由于该错误，我在位置中添加了单个索引，则在执行原始请求时“按位置查找，按类别排序2”“将对位置使用单一索引，忽略复合索引（category2，location）。使用普通索引（而不是2dsphere），则范围索引的工作是预期的，并在您发布的链接中解释。但是2dsphere索引不能作为范围搜索（地理位置搜索）的适当索引。”.有什么线索吗？我想在所描述的查询中使用地理索引后，您将始终处于排序阶段。