Re: TRUNCATE on foreign tables

On 2020-Jan-01, Kohei KaiGai wrote:

> Hello,
>
> The attached patch adds TRUNCATE support on foreign table.
>
> This patch adds an optional callback ExecForeignTruncate(Relation rel)
> to FdwRoutine.
> It is invoked during ExecuteTruncateGuts, then FDW driver hands over
> the jobs related to complete "truncate on the foreign table".

I think this would need to preserve the notion of multi-table truncates.
Otherwise it won't be possible to truncate tables linked by FKs. I
think this means the new entrypoint needs to receive a list of rels to
truncate, not just one. (Maybe an alternative is to make it "please
truncate rel X, and be aware that relations Y,Z are also being
truncated at the same time".)

Looking at apache arrow documentation, it doesn't appear that it has
anything like FK constraints.

--
Álvaro Herrera https://www.2ndQuadrant.com/
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