scheduler in core

Hi,

I'm trying to figure out how difficult is this

What we need:
- a shared catalog
- an API for filling the catalog
- a scheduler daemon
- pg_dump support

A shared catalog
-------------------------
Why shared? obviously because we don't want to scan all database's
pg_job every time the daemon wake up.
Maybe something like:

pg_job (
oid -- use the oid as pk
jobname
jobdatoid -- job database oid
jobowner -- for permission's checking
jobstarttime -- year to minute
jobfrequency -- an interval?
jobnexttime or joblasttime
jobtype -- if we are going to allow plain sql or
executable/shell job types
jobexecute or jobscript
)

comments about the catalog?

An API for filling the catalog
-----------------------------------------
do we want a CREATE JOB SQL synatx? FWIW, Oracle uses functions to
create/remove jobs.

An scheduler daemon
--------------------------------
I think we can use 8.3's autovacuum daemon as a reference for this...
AFAIK, it's a child of postmaster that sleep for $naptime and then
looks for something to do (it also looks in a
catalog) and the send a worker to do it
that's what we need to do but...

for the $naptime i think we can autoconfigure it, when we execute a
job look for the next job in queue and sleep
until we are going to reach the time to execute it

i don't think we need a max_worker parameter, it should launch as many
workers as it needs

pg_dump support
--------------------------
dump every entry of the pg_job catalog as a CREATE JOB SQL statement
or a create_job() function depending
on what we decided

ideas? comments?

--
Atentamente,
Jaime Casanova
Soporte y capacitación de PostgreSQL
Asesoría y desarrollo de sistemas
Guayaquil - Ecuador
Cel. +59387171157