Questions about a script for regular backups

[Having failed to post this message via Gmane, I am sending it by e-mail]

Hello, all

In order to write a backup script in the Windows batch
language, I was reading the section "Migrating Repository
Data Elsewhere" from "Repository Maintenance":

   http://svnbook.red-bean.com/en/1.7/svn.reposadmin.maint.html

where I found the following interesting paragraph:

   Another neat trick you can perform with this
   --incremental option involves appending to an existing
   dump file a new range of dumped revisions. For example,
   you might have a post-commit hook that simply appends the
   repository dump of the single revision that triggered the
   hook. Or you might have a script that runs nightly to
   append dump file data for all the revisions that were
   added to the repository since the last time the script
   ran. Used like this, svnadmin dump can be one way to back
   up changes to your repository over time in case of a
   system crash or some other catastrophic event.

The book unfortunately does not seem to give any examples of
this usage, leaving the following questions:

  1. Is "appending" to be understood literally, that is
      using the >> operator on a previously existing dump
      file, or is it a figure of speach describing a
      supplementary dump file that shall be applied "on top"
      of a previous one?

  2. How does one determine the revision range for a
      routine incremental dump -- by calling
      `svnlook youngest' before dumping?

  3. Must the backup script somehow store the last revision
      in the dump between calls? If so, I shall have to
      keep in a file and not let anybody touch it.

-- 
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