Re: Does PostgreSQL support job?

> -----Message d'origine-----
> De : Owen Jacobson [mailto:ojacobson(at)osl(dot)com]
> Envoyé : mercredi, février 01, 2006 18:00
> À : Daniel Caune; pgsql-sql(at)postgresql(dot)org
> Objet : RE: [SQL] Does PostgreSQL support job?
>
> Daniel Caune wrote:
> > Hi,
> >
> > I try to find in the documentation whether PostgreSQL supports job,
> > but I miserably failed. Does PostgreSQL support job? If not, what
> > is the mechanism mostly adopted by PostgreSQL administrators for
> > running jobs against PostgreSQL? I was thinking about using
> > cron/plsql/sql-scripts on Linux.
>
> The answer really depends on what you mean by "jobs". If you have a
> database task that can be expressed as a series of commands with no
> interaction involved, you can just put those commands in a file (your-job-
> name.sql) and run it using psql and cron:
>
> # replace leading stars with cron time settings
> * * * * * psql your-database -i your-job-name.sql
>

Yes, that's it. A job is a task, i.e. set of statements, which is scheduled to run against a RDBMS at periodical times. Some RDBMS, such as SQL Server and Oracle, support that feature, even if such a feature is managed differently from a RDBMS to another.

OK. I get it. I will use cron and psql as I was planning to do so.

> If you need something more complex, either a function which is executed
> from a script or a full-blown client program may be required. IME that's
> fairly rare.
>

I'm not sure to understand. Why calling a function from a script is different from executing a series of SQL commands? I mean, I can run a script defined as follows:

SELECT myjob();

where myjob is a stored procedure such as:

CREATE OR REPLACE FUNCTION myjob()
RETURNS void
AS $$
<a-lot-of-complex-stuff-here>
END;
$$ LANGUAGE PLPGSQL;

Does that make sense?

--
Daniel CAUNE