Mongodb 查询优化

A good writeup of how your index should be created is available in Optimizing MongoDB Compound Indexes. Let's take the main point of the article, where the compound index ordering should be equality --> sort --> range:

Your query "shape" is:

db.collection.find({category:..., _id: {$gt:...}})
             .sort({sticky:-1, lastPostAt:-1, _id:1})
             .limit(25)

We see that:

• category:... is equality
• sticky:-1, lastPostAt:-1, _id:1 is sort
• _id: {$gt:...} is range

So the compound index you need is:

{category:1, sticky:-1, lastPostAt:-1, _id:1}