mongodb 索引

创建索引

$collection --> 表名
$field --> 字段名
$value --> 值

# 1是正排, -1 是倒排
db.$collection.createIndex({$field:1});
 
# 建立复合索引 db.$collection.createIndex({$field1:1, $field2:1});

查看索引

db.$collection.getIndexes();

 

删除索引

db.$collecion.dropIndex({$field:1});

# 删除全部索引
db.$collection.dropIndexes();

 查看查询语句性能

db.$collecion.find({$field:$value}).explain(true)

 

  1 /* 1 */
  2 {
  3     "queryPlanner" : {
  4         "plannerVersion" : 1,
  5         "namespace" : "hdb_broker.hdb_dr_recommend",　　　　　　 //该值返回的是该query所查询的表
  6         "indexFilterSet" : false,　　　　　　　　　　　　　　　　　　//该query是否有indexfilter
  7         "parsedQuery" : {
  8             "$and" : [ 
  9                 {
 10                     "cntInfo.cntName" : {
 11                         "$eq" : "张三0"
 12                     }
 13                 }, 
 14                 {
 15                     "cntInfo.cntPhone" : {
 16                         "$eq" : "13784647210"
 17                     }
 18                 }
 19             ]
 20         },
 21         "queryHash" : "4159AA83",
 22         "planCacheKey" : "BDF6F710",
 23         "winningPlan" : {　　　　　　　　　　　//查询优化器针对该query所返回的最优执行计划的详细内容
 24             "stage" : "FETCH",　　　　　　　　//最优执行计划的stage，这里返回是FETCH，可以理解为通过返回的index位置去检索具体的文档
 25             "filter" : {
 26                 "cntInfo.cntPhone" : {
 27                     "$eq" : "13784647210"
 28                 }
 29             },
 30             "inputStage" : {
 31                 "stage" : "IXSCAN",
 32                 "keyPattern" : {
 33                     "cntInfo.cntName" : 1.0
 34                 },
 35                 "indexName" : "cntInfo.cntName_1",
 36                 "isMultiKey" : false,
 37                 "multiKeyPaths" : {
 38                     "cntInfo.cntName" : []
 39                 },
 40                 "isUnique" : false,
 41                 "isSparse" : false,
 42                 "isPartial" : false,
 43                 "indexVersion" : 2,
 44                 "direction" : "forward",
 45                 "indexBounds" : {
 46                     "cntInfo.cntName" : [ 
 47                         "[\"张三0\", \"张三0\"]"
 48                     ]
 49                 }
 50             }
 51         },
 52         "rejectedPlans" : [ 
 53             {
 54                 "stage" : "FETCH",
 55                 "filter" : {
 56                     "cntInfo.cntName" : {
 57                         "$eq" : "张三0"
 58                     }
 59                 },
 60                 "inputStage" : {
 61                     "stage" : "IXSCAN",
 62                     "keyPattern" : {
 63                         "cntInfo.cntPhone" : 1.0
 64                     },
 65                     "indexName" : "cntInfo.cntPhone_1",
 66                     "isMultiKey" : false,
 67                     "multiKeyPaths" : {
 68                         "cntInfo.cntPhone" : []
 69                     },
 70                     "isUnique" : false,
 71                     "isSparse" : false,
 72                     "isPartial" : false,
 73                     "indexVersion" : 2,
 74                     "direction" : "forward",
 75                     "indexBounds" : {
 76                         "cntInfo.cntPhone" : [ 
 77                             "[\"13784647210\", \"13784647210\"]"
 78                         ]
 79                     }
 80                 }
 81             }, 
 82             {
 83                 "stage" : "FETCH",
 84                 "filter" : {
 85                     "$and" : [ 
 86                         {
 87                             "cntInfo.cntName" : {
 88                                 "$eq" : "张三0"
 89                             }
 90                         }, 
 91                         {
 92                             "cntInfo.cntPhone" : {
 93                                 "$eq" : "13784647210"
 94                             }
 95                         }
 96                     ]
 97                 },
 98                 "inputStage" : {
 99                     "stage" : "AND_SORTED",
100                     "inputStages" : [ 
101                         {
102                             "stage" : "IXSCAN",
103                             "keyPattern" : {
104                                 "cntInfo.cntName" : 1.0
105                             },
106                             "indexName" : "cntInfo.cntName_1",
107                             "isMultiKey" : false,
108                             "multiKeyPaths" : {
109                                 "cntInfo.cntName" : []
110                             },
111                             "isUnique" : false,
112                             "isSparse" : false,
113                             "isPartial" : false,
114                             "indexVersion" : 2,
115                             "direction" : "forward",
116                             "indexBounds" : {
117                                 "cntInfo.cntName" : [ 
118                                     "[\"张三0\", \"张三0\"]"
119                                 ]
120                             }
121                         }, 
122                         {
123                             "stage" : "IXSCAN",
124                             "keyPattern" : {
125                                 "cntInfo.cntPhone" : 1.0
126                             },
127                             "indexName" : "cntInfo.cntPhone_1",
128                             "isMultiKey" : false,
129                             "multiKeyPaths" : {
130                                 "cntInfo.cntPhone" : []
131                             },
132                             "isUnique" : false,
133                             "isSparse" : false,
134                             "isPartial" : false,
135                             "indexVersion" : 2,
136                             "direction" : "forward",
137                             "indexBounds" : {
138                                 "cntInfo.cntPhone" : [ 
139                                     "[\"13784647210\", \"13784647210\"]"
140                                 ]
141                             }
142                         }
143                     ]
144                 }
145             }
146         ]
147     },
148     "serverInfo" : {
149         "host" : "hdb-dev-db-02",
150         "port" : 27017,
151         "version" : "4.2.5",
152         "gitVersion" : "2261279b51ea13df08ae708ff278f0679c59dc32"
153     },
154     "ok" : 1.0
155 }

 

posted @ 2020-07-14 11:20  泽文工作室  阅读(114)  评论(0)    收藏  举报