Timed Triggers?

This may seem a little silly, but I'd like to request a feature to
implement timed triggers.

With the number of cron jobs that run a perl script which runs a simple
SELECT function(); that does various nightly cleanup or maintenance
(billing run) it would be much nicer to have an actual trigger run every
12 hours rather than be initiated by a cron job.

Less places things could go wrong. Could be requested to run only when
a table isn't being used at the time (low priority maintenance). The
same thing could be implemented for a periodic vacuum.

I'd like to take this up myself, but will need to learn alot about the
way Postgres works first so if someone else sees the need as well please
feel free to implement (It'll take me atleast 6 months before I feel
comfortable with the results).

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Rod Taylor
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