Re: Tuning/performance issue...

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От Bruce Momjian
Тема Re: Tuning/performance issue...
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Msg-id 200310040238.h942cHX12107@candle.pha.pa.us
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Ответ на Re: Tuning/performance issue...  (Rod Taylor <rbt@rbt.ca>)
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Rod Taylor wrote:
-- Start of PGP signed section.
> On Fri, 2003-10-03 at 21:39, Bruce Momjian wrote:
> > I have updated the FAQ to be:
> >
> >       In comparison to MySQL or leaner database systems, we are
> >       faster for multiple users, complex queries, and a read/write query
> >       load.  MySQL is faster for SELECT queries done by a few users.
> >
> > Is this accurate?  It seems so.
>
> May wish to say ... for simple SELECT queries ...

Updated.

> Several left outer joins, subselects and a large number of joins are
> regularly performed faster in PostgreSQL due to a more mature optimizer.
>
> But MySQL can pump out SELECT * FROM table WHERE key = value; queries in
> a hurry.
>
>
> I've often wondered if they win on those because they have a lighter
> weight parser / optimizer with less "lets try simplifying this query"

I think that is part of it.

> steps or if the MYISAM storage mechanism is simply quicker at pulling
> data off the disk.

And their heap is indexed by myisam, right. I know with Ingres that Isam
was usually faster than btree because you didn't have all those leaves
to traverse to get to the data.

--
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
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  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

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