Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL

From: Bruce Momjian <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: chris(at)bitmead(dot)com
Cc: Don Baccus <dhogaza(at)pacifier(dot)com>, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>, pgsql-hackers(at)postgreSQL(dot)org, pgsql-sql(at)postgreSQL(dot)org
Subject: Re: [HACKERS] Re: [SQL] Proposed Changes to PostgreSQL
Date: 2000-02-03 12:09:18
Message-ID: 200002031209.HAA20081@candle.pha.pa.us
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> 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
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