Re: Brain dump: btree collapsing

>>>Justin Clift said:
> <snip>
> > In theory, if we find recyclable page(s) at the physical end of the index,
> > we could truncate the file (ie, give the space back to the filesystem)
> > instead of reporting these pages to FSM. I am not sure if this is worth
> > doing --- in most cases it's likely that little space can be released this
> > way, and there may be some tricky locking issues.
>
> Sounds like this would be beneficial for environments with high
> update/delete transaction volumes, perhaps on smaller amounts of
> live/valid data.

But if dead pages are removed (returned to FSM?) as soon as last item is
removed from the page, the page usage will remain small. Or perhaps not?

That is, it's unlikely to collect large number of dead/free pages at the end
of the physical storage except if doing all this in single VACUUM session.

Daniel