On Mon, Feb 10, 2020 at 4:35 AM Marc <postgres@xxxxxxxxxx> wrote: > We will keep the 12.1 in place so that we can run additional tests to assist to pin-point the issue. > > Feel free to ask but allow us to recover from these hectic days ;-) Here's how to get a stack so we can see what it was doing, assuming you have the Apple developer tools installed: 1. Find the PID of the backend you're connected to with SELECT pg_backend_pid(). 2. "lldb -p PID" from a shell to attach to the process, then "cont" to let it continue running. 3. Run the query in that backend and wait for the SIGKILL. 4. In the lldb session, type "bt". It'll only make sense if your PostgreSQL build has debug symbols, but let's see.