@87c34046 @f6beb887 [CursorWindow](https://developer.android.com/reference/android/database/CursorWindow) just buffers the rows in memory, so it's still slow whenever you move the window. This means it has to read the data from the storage. In this aspect the memory usage is similar to preloading, except in the old days we ran the IO operation in the main thread, which was causing laggy experience for users, but now we should have learned our lessons. 

 @f6beb887 @87c34046 I struggle to understand "the query will be super fast" it's super fast respect to network, but it's still an IO operation on disk, which is slow respect to anything in the main thread. I know we did that in old days, but it was not a good idea. Also based on your known knowledge of these subjects, I think either you are testing the Internet, or you are thinking far outside the box 😅 

 @87c34046 I remember when I was reading those code I got headaches. The question is why didn't people learn the lesson to avoid such a situation?(looking at fairly recently implemented sync function in Snapshot.kt file in Compose runtime)