Re: Batch API for After Triggers

On Sat, Jun 8, 2013 at 5:00 PM, Simon Riggs <simon(at)2ndquadrant(dot)com> wrote:
> While fiddling with FK tuning, Noah suggested batching trigger
> executions together to avoid execution overhead.
>
> It turns out there is no easy way to write triggers that can take
> advantage of the knowledge that they are being executed as a set of
> trigger executions. Some API is required to allow a trigger to
> understand that there may be other related trigger executions in the
> very near future, so it can attempt to amortise call overhead across
> many invocations ("batching").
>
> The attached patch adds two fields to the TriggerDesc trigger
> functions are handed, allowing them to inspect (if they choose) the
> additional fields and thus potentially use some form of batching.

I'm unclear how this could be used in practice. Are the events in a
"batch" guaranteed to, say, all be related to the same relation?

--
Robert Haas
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