For those who are interested in the internals:
http://postgresql.fastware.com/blog/fujitsu_advanced_postgresql_talk_1
Gavin Sherry is Australia's leading PostgreSQL expert, and a prominent
PostgreSQL community member.
Gavin recently gave an enlightening tech talk on the internals of
PostgreSQL, in which he discussed functionality such as Write-Ahead
Logging (WAL) in great detail, and explored various other issues which
may be of relevance to PostgreSQL DBAs everywhere.
http://video.google.com.au/videoplay?docid=5745755015991749390
Mark