Re: Vacuum thoughts

Greg Stark <gsstark@MIT.EDU> writes:

> Tom Lane <tgl@sss.pgh.pa.us> writes:
> 
> > You keep ignoring the problem of removing index entries.  To vacuum an
> > individual page, you need to be willing to read in (and update) all
> > index pages that reference the tuples-to-be-deleted.  
> 
> Hm. If the visibility information were stored in the index then that could be
> postponed and done when the index page was read or when it was flushed.

Or possibly if we could reuse the space in the table without updating the
index and be able to recognize that the tuple no longer corresponded to the
index entry when we next saw the index entry.

I suspect that would take as much space to keep track of as the visibility
information though.

-- 
greg