Hi,
Robert Treat wrote:
> Link added.
Thank you.
> 1st paragraph -> "everything less hurts ACID principles and thus isn't
> transparent to the application"; ACIDity doesn't control transparancy to
> application, so I would remove the "thus"
Hm.. a database which isn't ACID compliant isn't "transparent" to an
application which expects an ACID compliant database. But you are right,
not all applications require full ACIDity.
> Single Master vs. MM -> I think you should mention that single master is
> commonly reffered to as "master-slave".
Good tip, thanks.
> Also you should add an explicit
> example of what MM is.
Hm.. not sure, my primary goal is giving good definitions. Examples are
good for understanding, but normally aren't general enough. I'll give it
a try.
> Eager vs. Lazy -> these terms are pretty nebulous in the literature, and your
> definitions didnt resonate with me. But I don't disagree with it either :-)
Yeah, they are nebulous. The main reason for this nifty distinction is,
that the Postgres-R algorithm isn't synchronous in the common sense. But
it replicates data *before* committing to avoid convergence (and
conflicts). So it's eager, but asynchronous.
> Also, I think you need to add a section on shared nothing vs. shared
> everything.
Ah... at a certain point during writing that doc, that came to my mind,
but then it immediately disappeared. I only remembered that there was
yet another pair of terms. Thank you very much for reminding me.
> And maybe also explain vertical partitioning vs. horizontal
> partitioning (aka sharding).
Okay, I'll add that as well, makes sense.
> While the first has pretty much nothing to do
> with replication,
Well, you could spread the vertically partitioned tables across multiple
nodes, thus requiring distributed querying. There's almost nothing which
doesn't touch replication. And most things only add complexity ;-)
Thank you for your review.
Regards
Markus
