sparse index
常见例句
- Currently a sparse index can have only one field.
目前，Sparse索引只能有一个字段。 - Covering indexes allow data storage within the index itself while sparse indexes exclude documents that do not contain the missing field.
Covered索引允许在索引本身里存储数据，而 Sparse索引则会排除掉不包含索引字段的文档。 返回 sparse index