Re: Postgres v MySQL 5.0

Quoth johncwang(at)gmail(dot)com ("John Wang"):
> On 10/27/06, Joshua D. Drake <jd(at)commandprompt(dot)com> wrote:
>
>
> John Wang wrote:
> > On 10/27/06, Josh Berkus <josh(at)agliodbs(dot)com> wrote:
> >>
> >> Generally we try to avoid the MySQL
> >> comparison because it's not doing open source in general any good to
> >> constantly have PostgreSQL and MySQL pitted against each other.  We'd
> >> rather be compared with Oracle and DB2.
> >
> >
> > IMO, that's fine if you only want Oracle and DB2 users and want to let all
> > the other sites run MySQL. Is that the case?
>
> Well I typically look at it from a MySQL can't compare to PostgreSQL but
> PostgreSQL can compare to Oracle or DB2. That is the argument I use when
> comparing MySQL to PostgreSQL.
>
>
> Right now I typically look at the comparison as PostgreSQL isn't
> proven to scale as well as MySQL for Web 2.0 type community
> sites. It seems like all Alexa 100 sites that use a OSS database use
> MySQL (many of them on InnoDB). I've also seen an old eWeek
> performance test run where Oracle and MySQL compare well from a
> scalability perspective but MSSQL doesn't (Pg wasn't tested). In
> that case, MySQL, not Pg, was being compared against Oracle and
> MSSQL. I haven't found a single Alexa 100 site that runs PostgreSQL
> yet. If the Pg community doesn't want to compare itself against
> MySQL, is the implicit recommendation that community type sites
> planning for growth should use MySQL? That's fine if it is. I'm just
> curious.

That conclusion seems entirely opposite to the usual perspective that
comes out on scalability.

- MySQL(tm), with MyISAM, simply can't scale past ~ 10 heavily updating
users, table locking being a prohibitively troublesome problem

- MySQL(tm) with InnoDB(tm) seems likely to be a performance loss, as
compared to MyISAM, for small installations, but likely goes
further, in terms of being able to scale to larger numbers of
concurrent updates.

It's probably comparable to older versions of PostgreSQL in that
fashion. Jan Wieck did some benchmarking on a TPC-W-like test that
showed that there weren't material differences between InnoDB and
PostgreSQL for moderate loads.

- It's on PostgreSQL where people are finding it worthwhile to head
to much heavier levels of "scalability," where we're deploying
many-CPU heavy iron boxes alongside disk array technology.

"Web 2.0" strikes me as being fairly much a nonsequitor in all of
this. "Web 2.0" applications are ones whose purpose is to integrate
information from various web services. So, if you get an address, you
send a request to Google Maps to get location information and such.
There's NO database work involved in that.

There is the fairly obvious implication that if your primary
bottlenecks are in sending web service requests off to remote places,
then database scalability becomes *less* of a factor in the
application.

That seems to fit with the notion that MySQL(tm) represents a
reasonable answer for "Web 2.0"; if database throughput isn't a
bottleneck, then you can use even *less scalable* databases for those
sorts of applications.
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