[Pacemaker] PostgreSQL replicarion RA: PGSQL.lock

[Andrew]

Hi all.
For what reason is implemented PGSQL.lock in RA, and what pbs may happen 
if it'll be removed from RA code?

Also, 2nd question: how I can prevent pgsql RA from promoting master 
before both nodes will brings up OR before timeout is reached (for ex., 
if 2nd node is dead)? I think that clone of Delay RA for both nodes (to 
avoid switching delay on node with Delay resource failure) will do this 
- but I can't find how I should write such rule, it seems like rules in 
Pacemaker are too simple (or too bad described). I expect something like 
this (in <> braces I included rules that I don't know how to write):

location pgsql_master_location ms_Postgresql \
     rule $role="master" -inf: <Delay RA is not running> and 
<ms_Postgresql count eq 1>

Is this possible?