多键索引从包含数组值的字段中收集数据并进行排序。多键索引可提高对数组字段的查询性能。 您无需显式指定多键类型。对包含数组值的字段创建索引时,MongoDB 会自动将该索引设为多键索引。 MongoDB 可以在包含标量值(例如字符串和数字)和嵌入式文档的数组上创建多键索引。 如果数组包含同一值的多个实例,则索引仅包...
分片键可以是单个索引字段,也可以是复合索引涵盖的多个字段,复合索引决定集合文档在集群分片中的分布。 MongoDB 将分片键值(或哈希分片键值)的取值区间划分为不重叠的分片键值(或哈希分片键值)范围。每个范围都与一个数据块相关联,MongoDB 会尝试在集群中的各个分片之间均匀分配这些数据块。
Failed global initialization:BadValue Invalid or no user locale set.Please ensureLANGand/orLC_*environment variables aresetcorrectly.解决办法:[root@centos6-vm01~]# vim/etc/profile...exportLC_ALL=C[root@centos6-vm01~]# source/etc/profile--- 1)MongoDB命令帮助系统在安装MongoDB后,启动服务器进程...
Gets known MongoDbAuthenticationType values. Returns: known MongoDbAuthenticationType values.Applies to Azure SDK for Java LatestCollaborate with us on GitHub The source for this content can be found on GitHub, where you can also create and review issues and pull requests. For more information,...
import{Query}from"mingo";// input is either an Array or any iterable source (i.e Object{next:Function}) including ES6 generators.letcriteria={score:{$gt:10}};letquery=newQuery(criteria);// filter collection with find()letcursor=query.find(collection);// alternatively use shorthand// cursor...
A MongoDB Query Filter. The findOne action returns the first document in the collection that matches this filter. projection projection object A MongoDB Query Projection. Depending on the projection the returned document will either omit specific fields or include only specified fields or values ...
If multiple documents match, replaceOne will replace the first matching document only. db.collection.bulkWrite([ { replaceOne : { "filter" : <document>, "replacement" : <document>, "upsert" : <boolean>, "collation": <document>, // Available starting in 3.4 "hint": <document|string> /...
public function notIncludeGroup($filterName, array $value) public function range($filterName, $firstValue, $secondValue) public function notRange($filterName, $firstValue, $secondValue) public function notContain($filterName, $value) public function contain($filterName, $value) ...
A MongoDB Query Filter. The findOne action returns the first document in the collection that matches this filter. projection projection object A MongoDB Query Projection. Depending on the projection the returned document will either omit specific fields or include only specified fields or values ...
When you set up your MongoDB source endpoint, you can specify multiple endpoint configuration settings using the AWS DMS console. The following table describes the configuration settings available when using MongoDB databases as an AWS DMS source. Setting (attribute)Valid valuesDefault value and ...