Postgres query plan viewer

This will draw postgres query plans (from EXPLAIN and friends) in a form which may well be easier for you to parse.

http://www.dbplanview.com/

Postgres sql basic querying based on datetime

For the benefit of google (and me when I’m using google)

In postgres and probably most other SQLs the following

SELECT * FROM table where creation_date > timestamp 'now' - interval '2 hours';

finds all records that were created in the last 2 hours.

See also:
http://www.postgresql.org/docs/8.0/static/datatype-datetime.html