Re: why do we need two snapshots per query?

On Sun, Nov 13, 2011 at 4:09 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:

> As far as partitioning goes, the correct solution there
> is to move the partition selection to run-time, so we should not be
> contorting query semantics to make incremental performance improvements
> with the existing partitioning infrastructure.

Agreed, but I think we need both planning and execution time
awareness, just as we do with indexonly.

That's what I'd like to be able to do: link planning and execution.

It's all very well to refuse individual cases where linkage is
required, but ISTM clear that there are many possible uses of being
able to tell whether a plan is one-shot or not and nothing lost by
allowing that information (a boolean) pass to the executor.

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 Simon Riggs                   http://www.2ndQuadrant.com/
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