Re: [HACKERS] 64-bit queryId?

Поиск
Список
Период
Сортировка
От Peter Geoghegan
Тема Re: [HACKERS] 64-bit queryId?
Дата
Msg-id CAH2-Wzk4VALL5bxYZ54jAFdFGzdrNZk00xMH8WbAJjzJLJ_aRg@mail.gmail.com
обсуждение исходный текст
Ответ на Re: [HACKERS] 64-bit queryId?  (Robert Haas <robertmhaas@gmail.com>)
Ответы Re: [HACKERS] 64-bit queryId?  (Peter Geoghegan <pg@bowt.ie>)
Re: [HACKERS] 64-bit queryId?  (Robert Haas <robertmhaas@gmail.com>)
Re: [HACKERS] 64-bit queryId?  (Tom Lane <tgl@sss.pgh.pa.us>)
Re: [HACKERS] 64-bit queryId?  (Alexander Korotkov <a.korotkov@postgrespro.ru>)
Список pgsql-hackers
On Sat, Sep 30, 2017 at 7:34 AM, Robert Haas <robertmhaas@gmail.com> wrote:
> Assuming, however, that you don't manage to prove all known
> mathematics inconsistent, what one might reasonably hope to do is
> render collisions remote enough that one need not worry about them too
> much in practice.

Isn't that already true in the case of queryId? I've never heard any
complaints about collisions. Most people don't change
pg_stat_statements.max, so the probability of a collision is more like
1%. And, that's the probability of *any* collision, not the
probability of a collision that the user actually cares about. The
majority of entries in pg_stat_statements among those ten thousand
will not be interesting. Often, 90%+ will be one-hit wonders. If that
isn't true, then you're probably not going to find pg_stat_statements
very useful, because you have nothing to focus on.

I have heard complaints about a number of different things in
pg_stat_statements, like the fact that we don't always manage to
replace constants with '?'/'$n' characters in all cases. I heard about
that quite a few times during my time at Heroku. But never this.

-- 
Peter Geoghegan


-- 
Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

В списке pgsql-hackers по дате отправления:

Предыдущее
От: Tom Lane
Дата:
Сообщение: Re: [HACKERS] Re: CREATE COLLATION does not sanitize ICU's BCP 47 language tags. Should it?
Следующее
От: Peter Geoghegan
Дата:
Сообщение: Re: [HACKERS] 64-bit queryId?