Reading recommendations - Mailing list pgsql-performance

Hi

I am looking for some references to literature. While we have used
PostgreSQL in the past for a fair number of smaller projects, we are
now starting to use it on a larger scale and hence need to get into
issues of performance optimisation and tuning. While I am OK with using
the EXPLAIN features, I am getting quite insecure when facing things
like the options in the postgresql.conf file. For example reading the
man page on fsync option, it tells me to "read the detailed
documentation before using this!" I then read the Admin guide where I
get told that the benefits of this feature are issue of debate, leaving
me with little help as to how to make up my mind on this issue. So I
turn to this mailing list, but starting reading in the archive realise
that compared to the knowledge standard here, I am as wise as a baby.

I have read most of Bruce Momjian's book on PostgreSQL (Can I update my
2001 edition somehow? ;-)
I have Sams' PostgreSQL Developer's Handbook (which is OK too), but
offers little to nothing on operational issues.
I have read most of the admin (and user) guide, but it does not help me
really understand the issues:
> CPU_INDEX_TUPLE_COST (floating point) Sets the query optimizer’s
> estimate of the cost of processing each index tuple during an index
> scan. This is measured as a fraction of the cost of a sequential page
> fetch.
No idea what this means! (And should I feel bad for it?)

I am an application programmer with a little UNIX know-how.

What books or sources are out there that I can buy/download and that I
should read to get to grips with the more advanced issues of running
PostgreSQL?

More on what we do (for those interested):
We use PostgreSQL mainly with its PostGIS extension as the database
backend for Zope-based applications. Adding PostGIS features is what
has started to cause noticeable increase in the server load.
We're using the GIS enabled system on this platform:
PostgreSQL 7.3.4
PostGIS 0.8
Zope 2.7.5
Python 2.3.5
(Database-based functions are written in PL/PGSQL, not python!!)

on a 2-CPU (450MHz Intel P3) Compaq box (some Proliant flavour)
With a SCSI 4-disk RAID system (mirrored and striped)
SunOS 5.8 (Which I think is Solaris 8)

The server is administrated by my host (co-located). We cannot easily
upgrade to a newer version of Solaris, because we could not find a
driver for the disk controller used in this server. (And our host did
not manage to write/patch one up.)

As a business, we are creating and operating on-line communities, (for
an example go to http://www.theguidlife.net) not only from a technical
point of view, but also supporting the communities in producing
content.

BTW. If you are a SQL/python programmer in (or near) Lanarkshire,
Scotland, we have a vacancy. ;-)

Cheers

Marc

--
Marc Burgauer

Sharedbase Ltd
http://www.sharedbase.com
Creating and supporting on-line communities