$searchMeta (aggregation)

searchMeta returns different types of metadata result documents for Atlas Search queries on the field or fields in an Atlas collection. 返回不同类型的元数据结果文档，用于对Atlas集合中的一个或多个字段进行Atlas搜索查询。The fields must be covered by an Atlas Search index. 这些字段必须包含在Atlas搜索索引中。See:

• Index Definitions to learn more about creating and managing Atlas Search indexes.索引定义，以了解有关创建和管理Atlas搜索索引的更多信息。
• Atlas Search Aggregation Pipeline StagesAtlas搜索聚合管道阶段 to learn more about the $searchMeta pipeline stage syntax, usage, and results.了解有关$searchMeta管道阶段语法、用法和结果的更多信息。