Re: Remaining beta blockers

On Fri, May 3, 2013 at 05:24:54PM +0200, Andres Freund wrote:
> On 2013-05-03 16:11:13 +0100, Greg Stark wrote:
> > On Fri, May 3, 2013 at 1:12 AM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
> > > I was more thinking of the idea of having some status on the first page
> > > that might need to change in a future release.
> >
> > Incidentally, another option might be to have a <relfilenode>.meta
> > fork that has information like this. It doesn't fundamentally change
> > anything but it does mean that code that doesn't need to know about it
> > doesn't need to know to skip the first page. It also means we could
> > maybe expand it more easily. There have been previous wishlist items
> > to have some meta information so external tools can more easily parse
> > the data without needing access to the full catalog for example.
>
> The problem with an extra metadata fork is that it essentially would
> double the files in a cluster and it would also noticeably increase the
> amount of open files we need.
> There have been quite some complaints about CREATE DATABASE speed, I
> am not sure we want to make it even slower :(

Agreed. We start to get into file system performance issues at that
point. I have often wondered if we need to create hash the files into
subdirectories for databases with many tables. Has anyone profiled
this?

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

+ It's impossible for everything to be true. +