Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL
От | Bruce Momjian |
---|---|
Тема | Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL |
Дата | |
Msg-id | 200002031209.HAA20081@candle.pha.pa.us обсуждение исходный текст |
Ответ на | Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL (Chris Bitmead <chrisb@nimrod.itg.telstra.com.au>) |
Список | pgsql-hackers |
> Don Baccus wrote: > > > > At 09:55 PM 2/2/00 -0500, Tom Lane wrote: > > > > >There is also a nontrivial performance penalty that would be paid > > >for reversing this default, because then every ordinary SQL query > > >would suffer the overhead of looking to see whether there are > > >child tables for each table named in the query. That *really* > > >doesn't strike me as a good idea. > > > > Thank you for pointing this out, because my first reaction to > > the proposal was "what's the overhead for SQL users"? > > > I just did a performance check on this. I found that the overhead > is one tenth of a millisecond on a Sun desktop workstation. Pretty > trivial, and I'm sure it can be improved. Good point. Has to be non-mearurable performance penalty because most people don't use it. Maybe you will need a system cache entry for this. -- Bruce Momjian | http://www.op.net/~candle pgman@candle.pha.pa.us | (610) 853-3000+ If your life is a hard drive, | 830 Blythe Avenue + Christ can be your backup. | Drexel Hill, Pennsylvania19026
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