The correct solution is to prompt the admin

[Henrique de Moraes Holschuh]

On Thu, 16 Nov 2006, Roberto C. Sanchez wrote:
> debconf (at package install time) or something in the prerm script at
> purge in order to ask the admin what to do about it.

postrm script, you mean. And while doing it, please remember that you must
*not* rely on debconf being present, so make sure the right thing happens if
it is not present (i.e. /etc/sasldb2 is left alone)...

-- 
  "One disk to rule them all, One disk to find them. One disk to bring
  them all and in the darkness grind them. In the Land of Redmond
  where the shadows lie." -- The Silicon Valley Tarot
  Henrique Holschuh