Re: explain analyze rows=%.0f

Поиск
Список
Период
Сортировка
От Ron Mayer
Тема Re: explain analyze rows=%.0f
Дата
Msg-id 4A249CE9.6050708@cheapcomplexdevices.com
обсуждение исходный текст
Ответ на Re: explain analyze rows=%.0f  (Euler Taveira de Oliveira <euler@timbira.com>)
Ответы Re: explain analyze rows=%.0f  (Simon Riggs <simon@2ndQuadrant.com>)
Список pgsql-hackers
Euler Taveira de Oliveira wrote:
> Robert Haas escreveu:
>> ...EXPLAIN ANALYZE reports the number of rows as an integer...  Any
>> chance we could reconsider this decision?  I often find myself wanting
>> to know the value that is here called ntuples, but rounding
>> ntuples/nloops off to the nearest integer loses too much precision.
>>
> Don't you think is too strange having, for example, 6.67 rows? I would confuse
> users and programs that parses the EXPLAIN output. However, I wouldn't object

I don't think it's that confusing.   If it says "0.1 rows", I imagine most
people would infer that this means "typically 0, but sometimes 1 or a few" rows.

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?


В списке pgsql-hackers по дате отправления:

Предыдущее
От: Joe Conway
Дата:
Сообщение: Re: dblink patches for comment
Следующее
От: Robert Haas
Дата:
Сообщение: Re: from_collapse_limit vs. geqo_threshold