I have added the following TODO:
        
        * Speed WAL recovery by allowing more than one page to be prefetched
        
          This involves having a separate process that can be told which pages
          the recovery process will need in the near future.
          http://archives.postgresql.org/pgsql-hackers/2008-02/msg01279.php


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Heikki Linnakangas wrote:
> Aidan Van Dyk wrote:
> > How difficult is it to parse the WAL logs with enough knowledge to know
> > what heap page (file/offset) a wal record contains (I haven't looked
> > into any wal code)?
> 
> Unfortunately there's no common format for that. All the heap-related 
> WAL records, insert, update and delete, have a 
> RelFileNode+ItemPointerData at the beginning of the WAL payload, but 
> update records have another ItemPointerData for the tid of the new tuple 
> in addition to that. And all indexam WAL records use a format of their own.
> 
> It would be nice to refactor that so that there was a common format to 
> store the file+block number touched by WAL record. Like we have for full 
> page images. That would useful for all kinds of external tools to parse 
> WAL files, like the read-ahead restore_command you envisioned.
> 
> -- 
>    Heikki Linnakangas
>    EnterpriseDB   http://www.enterprisedb.com
> 
> --
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-- 
  Bruce Momjian  <[EMAIL PROTECTED]>        http://momjian.us
  EnterpriseDB                             http://postgres.enterprisedb.com

  + If your life is a hard drive, Christ can be your backup. +

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