Обсуждение: full vacuum really slows down query

I have a query that takes 2 sec if I run it from a freshly restored
dump.  If I run a full vacuum on the database it then takes 30 seconds.

Would someone please comment as to why I would see a 15x slow down by
only vacuuming the DB?

I am using 8.3.1

> I have a query that takes 2 sec if I run it from a freshly restored dump.
>  If I run a full vacuum on the database it then takes 30 seconds.

What do the two plans look like? Can you post the explains?

-Nathan