Thread

  1. Documentation bug at: current/sql-vacuum.html, Notes

    Christophe Pettus <xof@thebuild.com> — 2023-07-26T17:39:41Z

    Isn't this backwards?
    
    > If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanup is completed.
    
    Indexes have line pointers, tables have tuples, so it should read:
    
    > If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanup is completed.
    
    
    
  2. Re: Documentation bug at: current/sql-vacuum.html, Notes

    Nathan Bossart <nathandbossart@gmail.com> — 2023-07-26T17:55:50Z

    On Wed, Jul 26, 2023 at 10:39:41AM -0700, Christophe Pettus wrote:
    > Isn't this backwards?
    > 
    >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead tuples and the table itself will accumulate dead line pointers that cannot be removed until index cleanup is completed.
    > 
    > Indexes have line pointers, tables have tuples, so it should read:
    > 
    >> If index cleanup is not performed regularly, performance may suffer, because as the table is modified indexes will accumulate dead line pointers and the table itself will accumulate dead tuples that cannot be removed until index cleanup is completed.
    
    I believe the current phrasing is correct.  VACUUM will be able to reclaim
    the tuple space in the heap, but the line pointers must remain until their
    corresponding index tuples are removed.
    
    -- 
    Nathan Bossart
    Amazon Web Services: https://aws.amazon.com
    
    
    
    
  3. Re: Documentation bug at: current/sql-vacuum.html, Notes

    Christophe Pettus <xof@thebuild.com> — 2023-07-26T18:12:42Z

    
    > On Jul 26, 2023, at 10:55, Nathan Bossart <nathandbossart@gmail.com> wrote:
    > 
    > 
    > I believe the current phrasing is correct.  VACUUM will be able to reclaim
    > the tuple space in the heap, but the line pointers must remain until their
    > corresponding index tuples are removed.
    
    Ah, right, thanks.