Caching…!!, its little bit hard to go in brief with single article. But will try to share my knowledge learnt from Heikki / Robert Haas / Bruce Momjian in short. In PostgreSQL, there are two layers, PG shared buffers and OS Page cache, any read/write should pass through OS cache(No bypassing till now). Postgres writes data on OS Page Cache and confirms to user as it has written to disk, later OS cache write’s to physical disk in its own pace.
Preloading or Caching the table in PostgreSQL is a tough task, because PostgreSQL doesnt offer a Single big synchronize-level memory managment. All the memories are independent. Caching is possible with the third party tools like memcached.
pgmemcache is a set of PostgreSQL user-defined functions(API’s) that provide an interface to memcached. pgmemcache, pre-requisites recommends to have libmemcached, however its also recommended to install memcached along with it. My presentation consist of installation/caching/monitoring using pgmemcache API’s.