如何获取 MongoDB 所有索引的使用情况和大小

Question

I am trying to get MongoDB indexes usage and size in the same output.

db.getCollection(collection).stats().indexSizes; gives sizes

and db.getCollection(collection).aggregate({ "$indexStats": {} }); gives just usage.

Is there a command to output both?

Answer 1

Both queries can be combined on intellishell, since it uses syntax similar to javascript we can run the following script.

db = db.getSiblingDB("your-db-name");
const collections = db.getCollectionNames();

const result = [];
for (const collection of collections) {
    const sizes = db.getCollection(collection).stats().indexSizes;
    const indexStats = db.getCollection(collection).aggregate({ "$indexStats": {} }).toArray();
    for (const index of indexStats) {
        index.collection = collection;
        index.size = sizes[index.name];
        result.push(index)
    }
}

print (result)

notice the conversion to .toArray() in order to loop easily over it.