Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient)
| От | a3a18850@telus.net |
|---|---|
| Тема | Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) |
| Дата | |
| Msg-id | 1112920211.4255d0934e23d@webmail.telus.net обсуждение исходный текст |
| Ответ на | Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane) |
| Список | pgsql-performance |
Дерево обсуждения
Plan for relatively simple query seems to be very inefficient
(Arjen van der Meijden,
)
Re: Plan for relatively simple query seems to be very inefficient (Steve Atkins, )
Re: Plan for relatively simple query seems to be very inefficient (Arjen van der Meijden, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Arjen van der Meijden, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) ("Jim C. Nasby", )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan (John A Meinel, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) ("Jim C. Nasby", )
Re: Recognizing range constraints (was Re: Plan for (Simon Riggs, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Bruno Wolff III, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Mischa, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (, )
Re: Plan for relatively simple query seems to be very inefficient ("Dave Held", )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Mischa, )
Re: Plan for relatively simple query seems to be very inefficient (Steve Atkins, )
Re: Plan for relatively simple query seems to be very inefficient (Arjen van der Meijden, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Arjen van der Meijden, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) ("Jim C. Nasby", )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan (John A Meinel, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: [HACKERS] Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) ("Jim C. Nasby", )
Re: Recognizing range constraints (was Re: Plan for (Simon Riggs, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Bruno Wolff III, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Mischa, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (Tom Lane, )
Re: Recognizing range constraints (was Re: Plan for relatively simple query seems to be very inefficient) (, )
Re: Plan for relatively simple query seems to be very inefficient ("Dave Held", )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Tom Lane, )
Re: Plan for relatively simple query seems to be very inefficient (Mischa, )
Quoting Tom Lane <>: > Mischa <> writes: > > Quoting Tom Lane <>: > >> WHERE a.x > b.y AND a.x < 42 > > > Out of curiosity, will the planner induce "b.y < 42" out of this? > > No. There's some smarts about transitive equality, but none about > transitive inequalities. Offhand I'm not sure if it'd be useful to add > such. The transitive-equality code pulls its weight [...] > but I'm less able to think of common use-cases for transitive > inequality ... Thanks. My apologies for not just going and looking at the code first. Equality-transitives: yes, worth their weight in gold. Inequality-transitivies: I see in OLAP queries (usually ranges), or in queries against big UNION ALL views, where const false inequalities are the norm. "a.x > b.y and a.x < c.z" comes up in OLAP, too, usually inside an EXISTS(...), where you are doing something analogous to finding a path.
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