I'm a db newb in general, looking to use mongoDB for the first time. Wondering what the performance would be like for a query similar to the following (O(n\*m) complexity) on a collection with 500K-1M documents. Basically, my question is: At what collection size would one likely start seeing performance issues for a query like this? TIA

```
db.albums.find(
  {
    genres: 'Alternative Rock' 
  } 
) 

```