Does running pg_dump on live db produce consistent backups? I have a 3GB database that is constantly modified and I need to make backups without stopping the server (Postgres 8.3).

My pg_dump runs for 5 minutes. What if the data is modified during the process? Do I get consistent backups? I don't want to find out when disaster strikes.

Postgres documentation http://www.postgresql.org/docs/8.3/static/app-pgdump.html doesn't say anything about this.
From the manual:


  It makes consistent backups even if the database is being used
  concurrently.


So yes, you can trust the backup. Of course, it's PostgreSQL, you can trust your data in PostgreSQL.