It does sound nice,something like cron?
We can use a scheduling algorithm, and can define a pool of tasks as well as a time constraint for the amount of time
whichcan be used for running the tasks.Then, a scheduling algorithm can pick tasks from the pool based on priorities
andthe time duration of a task.I can see a dynamic programming solution to this problem.
Atri
Sent from my iPad
On 20-Mar-2013, at 21:33, Thom Brown <thom@linux.com> wrote:
> On 19 March 2013 17:42, Thom Brown <thom@linux.com> wrote:
>> On 14 February 2013 18:02, Josh Berkus <josh@agliodbs.com> wrote:
>>> Folks,
>>>
>>> Once again, Google is holding Summer of Code. We need to assess whether
>>> we want to participate this year.
>>>
>>> Questions:
>>>
>>> - Who wants to mentor for GSOC?
>>>
>>> - Who can admin for GSOC? Thom?
>>>
>>> - Please suggest project ideas for GSOC
>>>
>>> - Students seeing this -- please speak up if you have projects you plan
>>> to submit.
>>
>> If anyone else has more projects ideas to suggest, please do share.
>> Students, please feel free to review the PostgreSQL Todo list for
>> inspiration: http://wiki.postgresql.org/wiki/Todo Of course ensure
>> you don't choose anything too ambitious or trivial.
>
> Okay, here's a random idea (which could be infeasible and/or
> undesirable). How about a way to internally schedule tasks using a
> background worker process (introduced in 9.2) to wake on each tick and
> run tasks?
>
> So:
>
> CREATE EXTENSION pg_scheduler;
> --
> schedule_task(task_command, task_priority, task_start, repeat_interval);
>
> SELECT schedule_task('REINDEX my_table', 1, '2012-03-20
> 00:10:00'::timestamp, '1 week'::interval);
>
> SELECT list_tasks();
>
> -[ RECORD 1 ]---+-----------------------
> task_id | 1
> task_command | REINDEX my_table
> task_priority | 1
> task_start | 2012-03-20 00:10:00-04
> repeat_interval | 7 days
> owner | postgres
>
> SELECT delete_task(1);
>
> Tasks would be run in sequence if they share the same scheduled time
> ordered by priority descending, beyond which it would be
> non-deterministic. Or perhaps additional worker processes to fire
> commands in parallel if necessary.
>
> Disclaimer: I haven't really thought this through.
>
> --
> Thom
>
>
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