Re: FDW-based dblink (WIP)

Peter Eisentraut <peter_e(at)gmx(dot)net> wrote:

> This patch is listed in the commitfest, but I think the consensus was
> that it needed some rework.

No doubt, but SQL/MED will require a lot of works. Can we split the work
into small parts? I intended FDW-based dblink to be one of the split jobs.

Here are some random considerations:

* Split dblink to connector and connection management layers.
Present dblink has own name-based connection management and error
handling routines, but I think we should share them amoung connectors.

* CREATE FOREIGN TABLE supports only select query in SQL standard.
I thnk we will still need to have free-style SQL executor like dblink
even when we support SQL/MED It is not a waste to include dblink in core.

* Consider interface of extensible connecter to be able to connect
other DBMSs. Especially, there are many differences in usage of 2PC.

* Automatic 2PC is very useful if we supports non-select query in SQL/MED.
It would be better to have some infrastructure for it.

Regards,
---
ITAGAKI Takahiro
NTT Open Source Software Center