Wolfgang Brandl wrote:
> We want to start processes controlled by a prostgres table which acts like crontab.
> So we want to start a background worker process which starts the defined functions.
>
> Is it possible to start from a background worker process a child process with a specific User.
> So this process can only acces the data for his authority.
> Like a SQL Intrusion with this definition nobody can start a process a Postgres superuser.
You normally do things like that on UNIX-like operating systems by
setting the "setuid" bit on the executable that you want to start
and transferring ownership to the desired user.
There is no other way for a non-root user like "postgres" to start
an executable as a different user.
Your setup seems complicated.
Why don't you have a daemon process running as root outside of PostgreSQL
that regularly checks the table and starts scheduled processes?
Yours,
Laurenz Albe