[HyperDB] Any advantage to partitioning on a single database server?

[Andy Skelton]

Jim McQuillan wrote:
> I've been doing more research into scaling a WordPress multi-site
> installation, and I've been under the assumption that partitioning the
> tables into multiple databases would be beneficial for a large installation
> (hypothetically 50,000 blogs).

At some point we decided to have multiple databases on a single
machine. Maybe it had something to do with the number of files in a
directory, or the number of hard drives in the machine; I never quite
understood it. Maybe Barry or Donncha can explain.

> I know that using multiple database server would definitely bring a
> performance enhancement, but we're starting with one... so is it even worth
> it to implement partitioning at all right now?

There is some measurable overhead to partitioning. So if you had two
blogs and you put them in separate partitions I assume there would be
a tiny downside and no measurable upside.

At some point (hopefully) you'll need to use partitioning due to
hardware limitations. When that time comes, you may or may not benefit
from any partitioning you did on the one first server. Your scheme
might have to be thrown out or it might actually make it easier to
migrate to a scaled-up system. The only guaranteed benefit is having
the experience of working with the more complex configuration.

Without further information I'd say proceed without partitioning.
Don't try to do all your scaling in advance; it doesn't work. Run some
experiments once you have real-world data and traffic.

Andy