Re: Horizontal scalability/sharding

On Sun, Aug 30, 2015 at 7:47 AM, Bruce Momjian <bruce(at)momjian(dot)us> wrote:
>
> I have recently increased my public statements about the idea of adding
> horizontal scaling/sharding to Postgres. I wanted to share with hackers
> a timeline of how we got here, and where I think we are going in the
> short term:
>
> 2012-2013: As part of writing my scaling talk
> (http://momjian.us/main/presentations/overview.html#scaling) studying
> Oracle RAC, and talking to users, it became clear that an XC-like
> architecture (sharding) was the only architecture that was going to allow
> for write scaling.
>

I think sharding like architecture is quite useful for certain kind of
workloads
where users can manage to arrange queries and data layout in an optimized
way which I hope users might agree to change if required. One thing to
consider here is what kind of scaling are we expecting in such a system and
is it sufficient considering we will keep focussed on this architecture for
horizontal scalability?
Generally speaking, the scaling in such systems is limited by the number of
profitable partitions user can create based on data and then cross-partition
transactions sucks the performance/scalability in such systems. I
understand that there is definitely a benefit in proceeding with sharding
like
architecture as there are already some PostgreSQL based forks which uses
such architecture, so if we follow same way, we can save some effort rather
than inventing or following some other architecture, however there is no
harm
is discussing pros and cons of some other architectures like Oracle RAC,
Google F1 or others.

With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com