Re: Brain dump: btree collapsing

Bruce Momjian <pgman@candle.pha.pa.us> writes:
> It would be nice if VACUUM FULL would be able to compress the actual
> index file and return unused space to the operating system.  REINDEX
> does this, but I was thinking of something a little lighter that could
> be done automatically as part of VACUUM FULL.

But indexes tend to be very dependent on physical layout.  You can't
just shove stuff around without thinking about the consequences.
Tables (heaps) are *much* more forgiving about that.

My feeling is that what we need to fix now is index bloat during normal
operation.  If you want the indexes to actually *shrink*, that's a job
for REINDEX.  Perhaps someday we can improve on that --- but let's not
blur our focus on the immediate problem.
        regards, tom lane