Re: PostgreSQL clustering VS MySQL clustering

Dawid Kuroczko <qnex42@gmail.com> writes:

> Quick thought -- would it be to possible to implement a 'partial VACUUM'
> per analogiam to partial indexes?

No.

But it gave me another idea. Perhaps equally infeasible, but I don't see why.

What if there were a map of modified pages. So every time any tuple was marked
deleted it could be marked in the map as modified. VACUUM would only have to
look at these pages. And if it could mark as free every tuple that was marked
as deleted then it could unmark the page.

The only downside I see is that this could be a source of contention on
multi-processor machines running lots of concurrent update/deletes.

--
greg