The trigger can be specified to fire on time condition?

[Jamal Ghaffour <Jamal(dot)Ghaffour(at)elios-informatique(dot)fr>]

Hi All,
I ' m using the postgresql datbase to stores cookies. Theses cookies 
become invalid after  30 mn and have to be deleted. i have defined a 
procedure that will
delete all invalid cookies, but i don't know how to call it in loop way 
(for example each hour).
I think that it  possible  because this behaivor is the same of the 
autovaccum procedure that handle the vaccum process every time (60s in 
default way).
After reading the documentation, it seems  that triggers can't handle 
this stuff .
how can i resolve the problem ?


Thanks

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