Re: default_stats_target WAS: Simple postgresql.conf wizard
От | Aidan Van Dyk |
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Тема | Re: default_stats_target WAS: Simple postgresql.conf wizard |
Дата | |
Msg-id | 20081202211035.GR26596@yugib.highrise.ca обсуждение исходный текст |
Ответ на | Re: default_stats_target WAS: Simple postgresql.conf wizard (Josh Berkus <josh@agliodbs.com>) |
Список | pgsql-hackers |
* Josh Berkus <josh@agliodbs.com> [081202 15:54]: > Do you have any idea how skewed the distribution of data for DBT3 is? If > values are being generated in relatively equal proportion, I'd expect > increasing DST to have little effect. The databases where higher DST is > useful is ones with skewed data distribution. > > Unfortunately, all the data examples I could point to are proprietary > customer databases :-( But no body's asking anybody to point out "skewed" data... I think it's *unanimous* that on skewed data, a higher stats target is needed for the skewed columns. The question is how much of a penalty the (majority of?) users with "normal" data columns will have to pay in stats/planning overhead to accomidate a blanket increase in DST for the (few?) skewed columns. I think Marks started to try and show that overhead/difference with real numbers. My (probably unsubstantiated) bias is showing, but nobody else has (yet) showed otherwise ;-) a. -- Aidan Van Dyk Create like a god, aidan@highrise.ca command like a king, http://www.highrise.ca/ work like a slave.
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