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mongo3.4.6mongodb文本索引不工作
嗨出口，我是新来的mongodb，我有一些索引问题。下面我创建的requestId（串）recordInfo集合内的文本索引：
db.getCollection（ “RecordInfo”）上的createIndex（{ “请求ID”： “文本”}）
但是当我尝试以下查询：
db.getCollection（ “RecordInfo”）找到（{ “请求ID”： “4513456313212313212aaaa”}）解释（ “executionStats”），你可以看到它不使用索引：
"executionStats" : {
"executionSuccess" : true,
"nReturned" : 1,
"executionTimeMillis" : 17,
"totalKeysExamined" : 0,
"totalDocsExamined" : 9998,
"executionStages" : {
"stage" : "COLLSCAN",
"filter" : {
"RequestId" : {
"$eq" : "4513456313212313212aaaa"
}
},
"nReturned" : 1,
"executionTimeMillisEstimate" : 21,
"works" : 10000,
"advanced" : 1,
"needTime" : 9998,
"needYield" : 0,
"saveState" : 78,
"restoreState" : 78,
"isEOF" : 1,
"invalidates" : 0,
"direction" : "forward",
"docsExamined" : 9998
}
},
然后我尝试下面的$ text：
db.getCollection（ “RecordInfo”）找到（{$文字：{$搜索： “4513456313212313212aaaa”}}）。解释（ “executionStats” ） 它给了我下面，我觉得相当不错的：
"executionStats" : {
"executionSuccess" : true,
"nReturned" : 1,
"executionTimeMillis" : 1,
"totalKeysExamined" : 1,
"totalDocsExamined" : 1,
"executionStages" : {
"stage" : "TEXT",
"nReturned" : 1,
"executionTimeMillisEstimate" : 0,
"works" : 5,
"advanced" : 1,
"needTime" : 3,
"needYield" : 0,
"saveState" : 0,
"restoreState" : 0,
"isEOF" : 1,
"invalidates" : 0,
"indexPrefix" : {
},
"indexName" : "RequestId_text",
"parsedTextQuery" : {
"terms" : [
"4513456313212313212aaaa"
],
"negatedTerms" : [ ],
"phrases" : [ ],
"negatedPhrases" : [ ]
},
"textIndexVersion" : 3,
"inputStage" : {
"stage" : "TEXT_MATCH",
"nReturned" : 1,
"executionTimeMillisEstimate" : 0,
"works" : 5,
"advanced" : 1,
"needTime" : 3,
"needYield" : 0,
"saveState" : 0,
"restoreState" : 0,
"isEOF" : 1,
"invalidates" : 0,
"docsRejected" : 0,
"inputStage" : {
"stage" : "TEXT_OR",
"nReturned" : 1,
"executionTimeMillisEstimate" : 0,
"works" : 5,
"advanced" : 1,
"needTime" : 3,
"needYield" : 0,
"saveState" : 0,
"restoreState" : 0,
"isEOF" : 1,
"invalidates" : 0,
"docsExamined" : 1,
"inputStage" : {
"stage" : "IXSCAN",
"nReturned" : 1,
"executionTimeMillisEstimate" : 0,
"works" : 2,
"advanced" : 1,
"needTime" : 0,
"needYield" : 0,
"saveState" : 0,
"restoreState" : 0,
"isEOF" : 1,
"invalidates" : 0,
"keyPattern" : {
"_fts" : "text",
"_ftsx" : 1
},
"indexName" : "RequestId_text",
"isMultiKey" : true,
"isUnique" : false,
"isSparse" : false,
"isPartial" : false,
"indexVersion" : 2,
"direction" : "backward",
"indexBounds" : {
},
"keysExamined" : 1,
"seeks" : 1,
"dupsTested" : 1,
"dupsDropped" : 0,
"seenInvalidated" : 0
}
}
}
}
},
但为什么蒙戈不使用默认情况下，指数，所以我用暗示来强制索引查询下面：
db.getCollection（“RecordInfo”）。find（{“RequestId”：“4513456313212313212aaaa”}）.hint（“RequestId_text”）。explain（“executionStats”），它给我这些，这不是很好：
"executionStats" : {
"executionSuccess" : true,
"nReturned" : 1,
"executionTimeMillis" : 93,
"totalKeysExamined" : 49378,
"totalDocsExamined" : 9998,
"executionStages" : {
"stage" : "FETCH",
"filter" : {
"RequestId" : {
"$eq" : "4513456313212313212aaaa"
}
},
"nReturned" : 1,
"executionTimeMillisEstimate" : 91,
"works" : 49379,
"advanced" : 1,
"needTime" : 49377,
"needYield" : 0,
"saveState" : 386,
"restoreState" : 386,
"isEOF" : 1,
"invalidates" : 0,
"docsExamined" : 9998,
"alreadyHasObj" : 0,
"inputStage" : {
"stage" : "IXSCAN",
"nReturned" : 9998,
"executionTimeMillisEstimate" : 50,
"works" : 49379,
"advanced" : 9998,
"needTime" : 39380,
"needYield" : 0,
"saveState" : 386,
"restoreState" : 386,
"isEOF" : 1,
"invalidates" : 0,
"keyPattern" : {
"_fts" : "text",
"_ftsx" : 1
},
"indexName" : "RequestId_text",
"isMultiKey" : true,
"isUnique" : false,
"isSparse" : false,
"isPartial" : false,
"indexVersion" : 2,
"direction" : "forward",
"indexBounds" : {
"_fts" : [
"[MinKey, MaxKey]"
],
"_ftsx" : [
"[MinKey, MaxKey]"
]
},
"keysExamined" : 49378,
"seeks" : 1,
"dupsTested" : 49378,
"dupsDropped" : 39380,
"seenInvalidated" : 0
}
}
},
要summaize，我想用指数或任何方法来查询请求ID字段，它是字符串列快。但如果我强迫使用索引，它似乎不适用于我，只会让我的查询变得更糟。但如果我以另一种方式使用索引，如下所示，我可以看到一个相当不错的查询。但我不能在这个字段上指定我想用这种方式查询。 。
db.getCollection（ “RecordInfo”）找到（{$文字：{$搜索： “4513456313212313212aaaa”}}）。解释（ “executionStats”）
全文搜索索引与“正常”索引非常不同。你需要知道何时使用哪个，Mongo不能仅仅为你做出决定。例如，全文索引只能找到完整的令牌，并且不能告诉你它在哪个列中找到它们。 – Thilo
这不是“文本”索引。你想要一个普通的b-tree索引。只需'db.getCollection（“RecordInfo”）。createIndex（{“RequestId”：1}）'然后执行标准查询。 –
@Thilo我们主要查询文档的字符串字段上的子字符串，这是正则表达式匹配，我应该使用什么样的索引？我猜这是坏的设计，有非常大的文件，这使得我从创建文本索引，因为很多期限列表大小限制违规？ – Long