Re: Should we warn against using too many partitions?

On Fri, 7 Jun 2019 at 06:54, Justin Pryzby <pryzby@telsasoft.com> wrote:
> > > >+    critical decision to make.  Not having enough partitions may mean that
> > > >+    indexes remain too large and that data locality remains poor which could
> > > >+    result in poor cache hit ratios.  However, dividing the table into too
> > > >+    many partitions can also cause issues.  Too many partitions can mean
> > > >+    slower query planning times and higher memory consumption during both
> > > >+    query planning and execution.  It's also important to consider what
> > > >+    changes may occur in the future when choosing how to partition your table.
> > > >+    For example, if you choose to have one partition per customer and you
> > > >+    currently have a small number of large customers, what will the
> > >
> > > have ONLY ?
> >
> > I assume you mean after the "have" before "one partition per
> > customer"?
>
> No, I meant "currently have ONLY".

I see, thanks for explaining. I've left that one out as I think adding
"only" would imply that having a small number of large customers is
less significant that a large number of small customers. I don't
really see why either of those has significance over the other, so I
think "only" is out of place there.

-- 
 David Rowley                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services