Re: [HACKERS] Open 6.5 items

On Sun, 6 Jun 1999, Bruce Momjian wrote:

> > Future TODO items ?
> > 
> > As far as I see,there's no consensus of opinion whether we would 
> > remove useless segments(I also think it's preferable if possible) or 
> > we would only truncate the segments(as my trial patch does).
> > 
> > Only Bruce and Ole objected to my opinion and no one agreed 
> > with me.
> > How do other people who would use segmented relations think ?  
> >   
> 
> I liked unlinking because it allowed old backends to still see the
> segments if they still have open file descriptors, and new backends can
> see there is no file there.  That seemed nice, but you clearly
> demostrated it caused major problems.  Maybe truncation is the answer. 
> I don't know, but we need to resolve this for 6.5.  I can't imagine us
> focusing on this like we have in the past few weeks.  Let's just figure
> out an answer.  I am on IRC now if someone can get on to discuss this. I
> will even phone someone in US or Canada to discuss it.
> 
> What is it on the backend that causes some backend to think there is
> another segment.  Does it just go off the end of the max segment size
> and try to open another, or do we store the number of segments
> somewhere. I thought it was the former in sgml() area.  I honestly don't
> care if the segment files stay around if that is going to be a reliable
> solution.

Other then the inode being used, what is wrong with a zero-length segment
file?

Marc G. Fournier                   ICQ#7615664               IRC Nick: Scrappy
Systems Administrator @ hub.org 
primary: scrappy@hub.org           secondary: scrappy@{freebsd|postgresql}.org