Re: Catalog bloat (again)

On 28 January 2016 at 00:13, Bill Moran <wmoran(at)potentialtech(dot)com> wrote:

> On Wed, 27 Jan 2016 23:54:37 +0100
> Ivan Voras <ivoras(at)gmail(dot)com> wrote:
>
> > So, question #1: WTF? How could this happen, on a regularly vacuumed
> > system? Shouldn't the space be reused, at least after a VACUUM? The issue
> > here is not the absolute existence of the bloat space, it's that it's
> > constantly growing for *system* tables.
>
> With a lot of activity, once a day probably isn't regular enough.
>
>
I sort of see what you are saying. I'm curious, though, what goes wrong
with the following list of expectations:

1. Day-to-day load is approximately the same
2. So, at the end of the first day there will be some amount of bloat
3. Vacuum will mark that space re-usable
4. Within the next day, this space will actually be re-used
5. ... so the bloat won't grow.

Basically, I'm wondering why is it growing after vacuums, not why it exists
in the first place?