Why the Oplog decreasing Mongodb

Question

What type of query generates a decrease in the oplog? How do I find out which queries are affecting my oplog decrease (when comparing month to month)? Could you help me?

Answer 1

Oplog 窗口受到大量写入查询的影响，特别是大尺寸文档的大量删除，因为单个范围删除操作在 oplog 中分解为多个单独的删除查询。

Answer 2

谢谢@r2d2，我是如何发现查询受到影响的？