Daily checks help

HI All

I need some help once again.

I can't seem to figure out how the stat collector work or
for that matter how to retrieve the data (I am used to MySQL and don't
understand the workings and setup of postgresql that well as yet).

Let me give you guys some background information (some may
recognize it from a previous question) and then I will post my question.

Background:

- We have a client who is currently running about 15 servers and
spread across these are a total of 190 databases that they have created over
time (consolidation and archiving exercise is still underway).

- We were asked to look at the optimisation of the systems,
integration into Nagios checks and to implement daily health checks and
backups.

What I need to find out about:

. Seeing that there are o many databases, obviously the vacuuming is
done on a per database / table basis.

o Is there a better way of checking the last vacuum date/time and whether
it was successful or produced errors?

o Same goes for analysing of tables

. Databases sizes I can view manually using pgphpadmin (even though
there is quite a lot so working on this L )

. I am able to check for table locks using pgphpadmin as well
however this is also on a per database level.

o In terms of daily health checks, is there a better way of doing this?

. Database availability, I would like to rather do this on the
postgres instance level (i.e. if you can connect using psql then the
database is running).

o Is this correct or should this be tested on database level specifically.

. Will it be worthwhile to add the max_query_time and max open
transactions as well? I got this while testing check_postgres however not
sure if it is worth adding or not.

I would also appreciate any other suggestions of important things that need
to be checked and looked at on a daily basis.

Please keep in mind though that I am new to postgresql and still learning
the ropes but thank you in advance for all assistance.

Regards

Machiel