How to implement autostart of postgres?

Thank you all for your answers.

I'm using the Red Hat 5 OS. So I have no the 'upstart' utility at my
disposal. Unfortunately.

Yes, you are right, this is a question of database robustness. You know,
If any of postgres processes died the postmaster process will again
start up it. The main worry is if the postmaster process dies (truth be
told, I can reproduce it only using 'kill -KILL', which should be never
done, I know) and all other processes are up and running. All created
connections will go on with their work. And it means all db queries will
be processed after the postmaster died. Am I correct?

Is there any risk of losing of data or data corruption in this case?

There is any way to configure the postgres db like 'if the postmaster
process died all child processes are stopped'?

Undoubtedly the case of postmaster process dies should be investigated
to discover the root cause.

Best regards,

Irina