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
truncatethe file (ie, give the space back to the filesystem)> > instead of reporting these pages to FSM.  I am not sure
ifthis is worth> > doing --- in most cases it's likely that little space can be released this> > way, and there may be
sometricky locking issues.> > Sounds like this would be beneficial for environments with high > update/delete
transactionvolumes, 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