Re: Query progress indication - an implementation

On Mon, 2009-06-29 at 14:07 -0400, Tom Lane wrote:
> Josh Berkus <josh(at)agliodbs(dot)com> writes:
> > So, while an actual % completed indicator would be perfect, a "query
> > steps completed, current step =" would still be very useful and a large
> > improvement over what we have now.
>
> I think this is pretty much nonsense --- most queries run all their plan
> nodes concurrently to some extent. You can't usefully say that a query
> is "on" some node, nor measure progress by whether some node is "done".

The requirement is not nonsense, even if the detail was slightly off.

We can regard plans as acting in phases with each blocking node
separating the plan. We know which nodes those are, so we can report
that.

For each phase, it may be very hard to say what percentage is truly
complete, but we could at least report how much work has been done and
provide a percentage against planned numbers.

--
Simon Riggs www.2ndQuadrant.com
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