Re: Does PostgreSQL support job?

> -----Message d'origine-----
> De : Owen Jacobson [mailto:ojacobson@osl.com]
> Envoyé : mercredi, février 01, 2006 18:00
> À : Daniel Caune; pgsql-sql@postgresql.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 $$ 
END;
$$ LANGUAGE PLPGSQL;

Does that make sense?


--
Daniel CAUNE