Re: Proposal "VACUUM SCHEMA"

On 12/21/14, 3:30 PM, Fabrízio de Royes Mello wrote:
>
> On Sun, Dec 21, 2014 at 5:18 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us <mailto:tgl(at)sss(dot)pgh(dot)pa(dot)us>> wrote:
> >
> > =?UTF-8?Q?Fabr=C3=ADzio_de_Royes_Mello?= <fabriziomello(at)gmail(dot)com <mailto:fabriziomello(at)gmail(dot)com>> writes:
> > > I work with some customer that have databases with a lot of schemas and
> > > sometimes we need to run manual VACUUM in one schema, and would be nice to
> > > have a new option to run vacuum in relations from a specific schema.
> >
> > I'm pretty skeptical of this alleged use-case. Manual vacuuming ought
> > to be mostly a thing of the past, and even if it's not, hitting
> > *everything* in a schema should seldom be an appropriate thing to do.
> >
>
> I agree manual vacuum is a thing of the past, but autovacuum doesn't solve 100% of the cases, and sometimes we need to use it so my proposal is just do help DBAs and/or Sysadmins to write simple maintenance scripts.

Just one example of that is pre-emptively vacuuming during slower periods. Nothing spells "fun" like a freeze vacuum in the middle of a busy lunch period for a website.

Similarly, it's common to need to proactively vacuum after a data load, and since it's not unusual for there to be a schema dedicated to loading data, this makes that easier.

> > And why that, but not
> > say schema-wide ANALYZE, CLUSTER, TRUNCATE, ...
> >
>
> +1. I can write patches for each of this maintenance statement too.

If we're going to go that route, then perhaps it would make more sense to create a command that allows you to apply a second command to every object in a schema. We would have to be careful about PreventTransactionChain commands.
--
Jim Nasby, Data Architect, Blue Treble Consulting
Data in Trouble? Get it in Treble! http://BlueTreble.com