Re: The plan for FDW-based sharding

On Thu, Feb 25, 2016 at 01:53:12PM +0900, Michael Paquier wrote:
> > Well, as far as I know XC doesn't support data redistribution between
> > nodes and I saw good benchmarks of that, as well as XL.
>
> XC does support that in 1.2 with a very basic approach (coded that
> years ago), though it takes an exclusive lock on the table involved.
> And actually I think what I did in this case really sucked, the effort
> was centralized on the Coordinator to gather and then redistribute the
> tuples, at least tuples that do not need to move were not moved at
> all.

Yes, there is a lot of complexity involved in sending results between
nodes.

> >> Once that is done, we can see what workloads it covers and
> >> decide if we are willing to copy the volume of code necessary
> >> to implement all supported Postgres XC or XL workloads.
> >> (The Postgres XL license now matches the Postgres license,
> >> http://www.postgres-xl.org/2015/07/license-change-and-9-5-merge/.
> >> Postgres XC has always used the Postgres license.)
>
> Postgres-XC used the GPL license first, and has moved to PostgreSQL
> license exactly to allow Postgres core to reuse it later on if needed.

Ah, yes, I remember that now. Thanks.

--
Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
EnterpriseDB http://enterprisedb.com

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