Is the DynamoDB table design efficient for Monitoring System?

Question

I have to design a DynamoDB table for a Monitoring System.

The attributes present for each item are:

• name (Monitor Name: String)
• et (milliseconds epoch: Number)
• owner (Owner of the monitor: String)

Below are the queries that I need to perform:

1. Retrieve all monitors:
   1.1 That ran today
   1.2 In et (milliseconds epoch) range
2. Retrieve by owner and name
3. Retrieve by owner
4. Retrieve by owner, name, and in et (milliseconds epoch) range

I came up with below selection of keys:

• Partition Key: Owner#MonitorName
• Sort Key: ET (milliseconds epoch)
• GSI Partition Key: ET (milliseconds epoch)

How I think queries would be executed:

• Query 1:
  • Query 1.1 et = :val
  • Query 1.2 et between :val1 and :val2
• Query 2: Owner#MonitorName = :val
• Query 3: Owner#MonitorName begins_with(:val)
• Query 4: (Owner#MonitorName = :val) and (et between :val1 and :val2)

Is this design efficient? What are the drawbacks for the design? How can it be improved?