MongoDb geoIntersects不';不要随意使用

MongoDb geoIntersects不';不要随意使用,mongodb,indexing,explain,2dsphere,Mongodb,Indexing,Explain,2dsphere,我有一个名为search2的集合,其中包含大约20000个文档,如下所示: { "loc": { "type": "Polygon", "coordinates": [ [ [ 43.78526674007639, 11.14739998758569 ], [

我有一个名为search2的集合,其中包含大约20000个文档,如下所示:

    {
        "loc": {
        "type": "Polygon",
        "coordinates": [
            [
            [
                43.78526674007639,
                11.14739998758569
            ],
            [
                43.78526674007639,
                11.183372851822439
            ],
            [
                43.79443488391605,
                11.183372851822439
            ],
            [
                43.79443488391605,
                11.264311796355125
            ],
            [
                43.812771171595415,
                11.264311796355125
            ],
            [
                43.83110745927479,
                11.264311796355125
            ],
            [
                43.83110745927479,
                11.273305012414314
            ],
            [
                43.849443746954144,
                11.273305012414314
            ],
            [
                43.858611890793824,
                11.273305012414314
            ],
            [
                43.858611890793824,
                11.264311796355125
            ],
            [
                43.8769481784732,
                11.264311796355125
            ],
            [
                43.8769481784732,
                11.246325364236752
            ],
            [
                43.88611632231286,
                11.246325364236752
            ],
            [
                43.88611632231286,
                11.237332148177565
            ],
            [
                43.895284466152546,
                11.237332148177565
            ],
            [
                43.895284466152546,
                11.228338932118376
            ],
            [
                43.904452609992234,
                11.228338932118376
            ],
            [
                43.904452609992234,
                11.165386419704065
            ],
            [
                43.895284466152546,
                11.165386419704065
            ],
            [
                43.895284466152546,
                11.156393203644878
            ],
            [
                43.88611632231286,
                11.156393203644878
            ],
            [
                43.8769481784732,
                11.156393203644878
            ],
            [
                43.858611890793824,
                11.156393203644878
            ],
            [
                43.849443746954144,
                11.156393203644878
            ],
            [
                43.849443746954144,
                11.165386419704065
            ],
            [
                43.83110745927479,
                11.165386419704065
            ],
            [
                43.83110745927479,
                11.156393203644878
            ],
            [
                43.812771171595415,
                11.156393203644878
            ],
            [
                43.812771171595415,
                11.14739998758569
            ],
            [
                43.79443488391605,
                11.14739998758569
            ],
            [
                43.78526674007639,
                11.14739998758569
            ]
            ]
        ]
        },
        "docId": 1,
        "docVote": 0,
        "title": "title-1",
        "_id": {
        "$oid": "5248725d2dd5622510000001"
        }
    }
我使用以下命令定义索引:

    db.search2.ensureIndex({"loc":"2dsphere"});
集合上只有此索引和“\u id”字段上的默认索引

执行以下查询时,我希望解释中的indexOnly参数设置为true:

    db.search2.find({
        loc: {
        $geoIntersects: {
            $geometry: {
            type: "Polygon",
            coordinates: [
                [
                    [43.7269795, 11.1540365],
                    [43.7269796, 11.1540365],
                    [43.7269796, 11.1540366],
                    [43.7269795, 11.1540366],
                    [43.7269795, 11.1540365]
                ]
            ]
            }
        }
        }
    }, {
        loc: 1,
        _id: 0
    }).hint({"loc":"2dsphere"}).explain()
但结果是:

    {
        "cursor" : "S2Cursor",
        "isMultiKey" : true,
        "n" : 14,
        "nscannedObjects" : 14,
        "nscanned" : 186,
        "nscannedObjectsAllPlans" : 14,
        "nscannedAllPlans" : 186,
        "scanAndOrder" : false,
        "indexOnly" : false,
        "nYields" : 0,
        "nChunkSkips" : 0,
        "millis" : 20,
        "indexBounds" : {

        },
        "nscanned" : 186,
        "matchTested" : NumberLong(80),
        "geoTested" : NumberLong(80),
        "cellsInCover" : NumberLong(1),
        "server" : "*******"
    }
我注意到isMultiKey是真的,这是由文档多边形语法引起的。 游标是S2Cursor,所以我假设使用了索引。 但为什么indexOnly是假的?是由于多边形语法吗?那么不可能有IndexOnly=true吗?
提前感谢

来自各州的间接解释:

indexOnly是一个布尔值,当游标字段中指示的索引覆盖查询时,该值返回true。当一个索引 覆盖一个查询,MongoDB可以匹配查询条件并返回 结果仅使用索引,因为:

  • 查询中的所有字段都是该索引的一部分,并且

  • 查询中的所有字段都是该索引的一部分,并且

从中可以看出:

在以下情况下,索引不能覆盖查询:

  • 集合中任何文档中的任何索引字段都包含一个数组。如果索引字段是数组,则索引变为 多键索引,不支持覆盖查询
  • 任何索引字段都是子文档中的字段

希望它能有所帮助

我同意你的看法,但我如何才能使用$GEOCERSECTS进行查询,以及indexOnly在哪里是真的?从文件上看,这似乎是不可能的。这是真的吗?感谢您,从文档中我得出了相同的结论,因为多键索引不能覆盖查询。