While the query of the above example is running, these 45 seconds, there are one or partially two PostgreSQL procceses active, consuming 100 % CPU each.

Same with GVM 20 and PostgreSQL 13.

Thanks for the report.
Unfortunately we have to use the postgresql version present in Debian Testing (currently version 13).
I don't know anything about performance optimization for postgresql / gvmd. Patches are welcome.

I hope upstream will work on this soon.

Found this one about PostgreSQL optimization:

Found the answer to this issue in case anyone else runs across it, it’s JIT in Postgres 12.

Just edit postgresql.conf, find the commented out line that says jit = on, uncomment, change it to say jit = off, and postgres 12 works fine.

https://community.greenbone.net/t/everything-works-but-i-cant-see-any-report/5875/21

Wonderful, the hint with jit = off helped to solve the issue, also with GVM 20 and PostgreSQL 13.

Indeed wonderful. Not sure about the side effects of disabling JIT and if upstream can do something about it (i guess not if JIT of PostgreSQL could be responsible for this)

thanks for the hint.
I will add a note in the README.Debian of the gvm package

This report has been filed against an old version of Kali. We will be closing this ticket due to inactivity.

Please could you see if you are able to replicate this issue with the latest version of Kali Linux (https://www.kali.org/get-kali/)?

If you are still facing the same problem, feel free to re-open the ticket. If you choose to do this, could you provide more information to the issue you are facing, and also give information about your setup?
For more information, please read: https://www.kali.org/docs/community/submitting-issues-kali-bug-tracker/