Re: EXPLAIN and nfiltered, take two

On Thu, Sep 22, 2011 at 02:41:12AM -0400, Tom Lane wrote:
> Yeah, I thought seriously about that too.  The problem with it is that
> you end up having to print that line all the time, whether or not it
> adds any knowledge.  The "filter removed N rows" approach has the saving
> grace that you can leave it out when no filtering is happening.  Another
> point is that if you have two filters operating at a node, printing only
> the starting number of rows doesn't let you disentangle which filter did
> how much.

I wonder if it would be more useful to print a percentage. If 0% is
filtered out you can still drop it but it gives a more useful output if
the number of rows is really large.

Have a nice day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> He who writes carelessly confesses thereby at the very outset that he does
> not attach much importance to his own thoughts.  -- Arthur Schopenhauer