How can I see if queries are running on GPU or CPU?

You can use SQL commands to verify.

If you are not using Immerse, the easiest way to check is by using the heavysql command-line client, which you can find at $HEAVYAI_PATH/bin/heavysql

To start the client, use the command bin/heavysql -p HyperInteractive, where HyperInteractive is the default password.

If you're using Immerse, you can also execute the following steps using the SQL Editor in Immerse.

Use one of the following methods to see where your query is running:

1. Prepend the EXPLAIN command to a SELECT statement to see a representation of the code that will run on the CPU or GPU. The first line is important; it shows either IR for the GPU or IR for the CPU  -  This is the most direct method
2. The server logs show a message at startup stating if OmniSci has fallen back to CPU mode. The logs are in your $HEAVYAI_STORAGE directory (default /var/lib/heavyai/storage), in a directory named log.
3. If you are using Immerse, open up the control panel, and click on System Dashboards and open up the System Resources dashboard, Memory Utilization Tab.
   
   Alternatively, the \memory_summary heavysql command shows how much memory is in use on the CPU and each GPU. HEAVY.AI manages memory itself, so you will see separate columns for in use (actual memory being used) and allocated (memory assigned to heavydb, but not necessarily in use yet).