initskript after db start; locks on transactions - Mailing list pgsql-general

Hi!

I have have two questions:

1.
What is the best approach to trigger a service script wich will clean
up something in the db after every db (re-)start? Has PG its own
mechanism for such things or have i to use my /etc/init.d/postgresql
script?

2.
Sometime i read something about locks on transactions. Is this only an
internal thing or can i set them by my own and if yes, for what? With
the LOCK command i can only lock tables, or?

Thanks for any help,
Thomas!