Re: Mini improvement: statement_cost_limit
От | Hans-Jürgen Schönig |
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Тема | Re: Mini improvement: statement_cost_limit |
Дата | |
Msg-id | 9121EEE5-2C0E-4E58-8D8D-80665F120926@cybertec.at обсуждение исходный текст |
Ответ на | Re: Mini improvement: statement_cost_limit (Bruce Momjian <bruce@momjian.us>) |
Список | pgsql-hackers |
>> this entire thing is not about cartesian products at all. it is about kicking out "expensive" queries before they even start to eat up tons of CPU. imagine a user asking for "give me all phone call in the US within the past 10 years". you could kill the guy instantly because you know that this would take ages. in addition to that you know that in an OLTP context everything which is expected to take longer than X cannot be useful anyway. this has nothing to do with cartesian products or other bad things you can do in SQL. it is just a simple and heuristic check. many thanks, hans > My point is that people should _know_ they are using a cartesian > product, and a warning would do that for users who have no need for a > cartesian product and want to be warned about a possible error. > > -- > Bruce Momjian <bruce@momjian.us> http://momjian.us > EnterpriseDB http://enterprisedb.com > > + If your life is a hard drive, Christ can be your backup. + -- Cybertec Schönig & Schönig GmbH Gröhrmühlgasse 26 A-2700 Wiener Neustadt Web: www.postgresql-support.de
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