Re: [HACKERS] vacuum process size

> Tatsuo Ishii <t-ishii(at)sra(dot)co(dot)jp> writes:
> > I have tested your idea and found even more improved memory usage
> > (86MB vs. 43MB). Standard vacuum consumes as much as 478MB memory with
> > deleting 5000000 tuples that would not be acceptable for most
> > configurations. I think we should fix this as soon as possible. If
> > there's no objection, I will commit included patches to the stable
> > tree (seems Tom has more aggressive idea, so I'll leave the current
> > tree as it is).
>
> No, please make the change in current as well. I was thinking about
> tweaking aset.c to be smarter about releasing large chunks, but in any
> case having the doubling behavior at the request point will be a big
> improvement.
>
> I do not like your patch as given, however. By using a static variable
> you are assuming that there is only one active VPageList at a time.
> It looks to me like there are at least two --- and there is no reason
> to think they'd be the same size.
>
> You need to add a num_pages field to the VPageList struct, not use
> a static.

Good point. I have committed new patches that do not use static
variables anymore to both REL6_5_PATCHES and current tree.

Modified files: backend/commands/vacuum.c and
include/commands/vacuum.h.
---
Tatsuo Ishii