Thread

1. About TOAST and indices

   Jan Wieck <janwieck@t-online.de> — 2000-07-20T15:20:38Z

   Hi,
   
       up to now, TOAST would be a v7.1 show-stopper, because due to
       the upper-block btree references  problem,  it's  not  VACUUM
       safe  if there's a btree index on a toastable attribute (like
       text).
   
       The only clean way to get rid of these upper-block references
       is to recreate the indices from scratch, instead of vacuuming
       them in the crash-safe manner we do now. But doing  so  needs
       file  versioning,  and I don't expect it to be implemented in
       v7.1.
   
       So at the time  beeing,  I  think  index  tuples  should  not
       contain  any external toast references. I'll change the heap-
       am/toaster combo temporarily to do that.  All  that  will  be
       covered  by  #ifdef, so we can switch back easily at the time
       we have file versioning to unlimit indexed attribute sizes as
       well.
   
       Comments?
   
   
   Jan
   
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   # Let's break this rule - forgive me.                                  #
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2. Re: About TOAST and indices

   Tom Lane <tgl@sss.pgh.pa.us> — 2000-07-20T15:51:48Z

   JanWieck@t-online.de (Jan Wieck) writes:
   >     So at the time  beeing,  I  think  index  tuples  should  not
   >     contain  any external toast references.
   
   Seems like a good stopgap solution.  You'll still allow them to be
   compressed in-line, though, right?
   
   			regards, tom lane
   
   

3. Re: About TOAST and indices

   Jan Wieck <janwieck@t-online.de> — 2000-07-20T16:41:16Z

   Tom Lane wrote:
   > JanWieck@t-online.de (Jan Wieck) writes:
   > >     So at the time  beeing,  I  think  index  tuples  should  not
   > >     contain  any external toast references.
   >
   > Seems like a good stopgap solution.  You'll still allow them to be
   > compressed in-line, though, right?
   
       Of  course. There's no problem with in-line compressed items.
       It's only these external references that cause trouble  after
       a vacuum.
   
   
   Jan
   
   --
   
   #======================================================================#
   # It's easier to get forgiveness for being wrong than for being right. #
   # Let's break this rule - forgive me.                                  #
   #================================================== JanWieck@Yahoo.com #