Re: Catalog bloat (again)

On 01/27/2016 03:37 PM, Ivan Voras wrote:
>
>
> On 28 January 2016 at 00:13, Bill Moran <wmoran(at)potentialtech(dot)com
> <mailto:wmoran(at)potentialtech(dot)com>> wrote:
>
> On Wed, 27 Jan 2016 23:54:37 +0100
> Ivan Voras <ivoras(at)gmail(dot)com <mailto: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?

If something is causing the autovacuum to be aborted you can have this
problem.

JD

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