[Zope] One time persistent variable

[Antonio Beamud Montero]

Hi all:
How I can make a variable from a Product persistent, but only exists a
copy in the ZODB?, i.e. this variable is updated every 30 sec. and I
don't want ZODB saves all old states of this variable, only the last...
How I can make this...?

Thanks in advance
-- 
Microsoft merges technologies: 
Windows CE + Windows ME + Windows NT = Windows CEMENT

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Antonio Beamud Montero
Agora Systems S.A.

http://www.agoratechnologies.com