Re: Index speeds up one row table (why)?

On Sat, May 31, 2003 at 16:56:56 -0600,
  Dave E Martin XXIII <postgresql-to.dave@dave.to> wrote:
>
> (ok, experimented a bit more just now)
> Hm, it appears that degredation occurs with the index as well, I guess
> at the time I created the index, it just initially did better because it
> got to skip all the already dead rows at creation time: but this is
> disturbing, I do a vacuum, and the access times are better, but still
> horrible:

You really don't want to use an index, so this probably doesn't matter
for the current application. The problem is that when data is inserted
into an index that just increases (or decreases) in value space from
deleted entries doesn't get reused. I believe this is fixed in 7.4.
This case would apply to indexes based on counters, dates or times
where new values are added and old values get deleted.