Article:
  Drupal 6.0: Installation and Basic Usage
Subject:   PostgreSQL Works Fantastic With Drupal
Date:   2008-04-01 08:06:44
From:   darnold4
Response to: PostgreSQL Works Fantastic With Drupal

Because of the way Drupal interacts with the DB, it can use either. The difference comes when you start looking at modules. Many modules include only MySQL SQL. If you feel up to tweaking the module's SQL for PostgreSQL use, it should work transparently so everyone wins :-).