| From: | Robert Haas <robertmhaas(at)gmail(dot)com> |
|---|---|
| To: | Simon Riggs <simon(at)2ndQuadrant(dot)com> |
| Cc: | Ron Mayer <rm_pg(at)cheapcomplexdevices(dot)com>, Euler Taveira de Oliveira <euler(at)timbira(dot)com>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: explain analyze rows=%.0f |
| Date: | 2009-06-02 14:06:18 |
| Message-ID: | B8F900A1-1ACB-4C84-84D6-676B2B7DF8A2@gmail.com |
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| Lists: | pgsql-hackers |
On Jun 2, 2009, at 9:41 AM, Simon Riggs <simon(at)2ndQuadrant(dot)com> wrote:
>
> On Mon, 2009-06-01 at 20:30 -0700, Ron Mayer wrote:
>
>> What I'd find strange about "6.67 rows" in your example is more
>> that on
>> the estimated rows side, it seems to imply an unrealistically
>> precise estimate
>> in the same way that "667 rows" would seem unrealistically precise
>> to me.
>> Maybe rounding to 2 significant digits would reduce confusion?
>
> You're right that the number of significant digits already exceeds the
> true accuracy of the computation. I think what Robert wants to see is
> the exact value used in the calc, so the estimates can be checked more
> thoroughly than is currently possible.
Bingo.
...Robert
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