Re: [HACKERS] What can we learn from MySQL?

On Tue, Apr 27, 2004 at 07:55:08PM +0400, Alexey Borzov wrote:
> Hi!
>
> Tim Conrad wrote:
> >I was researching an article I wrote about a comparison between
> >Postgres and MySQL recently (If you want, you can read the article
> >at http://www.devx.com/dbzone/Article/20743/). I noticed some clear
> >differences between the mysql.com website and the Postgres website.
>
> Sorry, couldn't resist: may I suggest doing the research *before*
> writing an article, not *after*?
>
> My favourite part of it is:
> --------
> MySQL uses traditional row-level locking. PostgreSQL uses something
> called Multi Version Concurrency Control (MVCC) by default. MVCC is a
> little different from row-level locking in that transactions on the
> database are performed on a snapshot of the data and then serialized.
> New versions of PostgreSQL support standard row-level locking as an
> option, but MVCC is the preferred method.
> --------
Nice that you point out that incorrectly stated something. Even
nicer that you don't tell me what the correct answer would be.
Unfortunanatly, that's the best I could come up with with doing
research with the documentation I could find on the subject. MVCC
does a lot more than can be easily contained in a sentance.

>
> >2) There doesn't seem to be a clear roadmap on Postgres features.
> > When certian things are expected. There's the TODO list that
> > Bruce maintains, but it only outlines 'near' fixes. MySQL has a
> > nice listing of what to expect in certian future versions. I know
> > it's not a perfect list, but it'd be nice to know when full blown
> > replication will be included in PostgreSQL as an example.
>
> MySQL's roadmap is complete bullshit. Subselects were first promised in
> 4.0, which was "not that far away" [1] back in 1998! Well, they are in
> 4.1, which is still alpha in 2004.

I realize this. I also realize that having a nicely defined roadmap would
give Postgres a hands up in this category.

>
> Of course, some gullible people actually believe this and compare [2]
> the existing and working implementations with vaporware (MySQL 5.1,
> anyone?).
>
> > On those same lines, there doesn't seem to be anything about the
> > improvements in the minor versions. It seems that in every
> > release (i.e. 7.2,7.3,7.4) there are pretty significant changes,
> > but finding a place that outlines these changes is somewhat
> > difficult.
>
> Have you tried looking in the release notes [3]?
>
>
> [1] http://www.geocrawler.com/archives/3/194/1998/8/0/1061364/
> [2] http://www.devx.com/dbzone/Article/20743/1763?supportItem=1
> [3] http://www.postgresql.org/docs/7.4/interactive/release.html

I guess I'm an ignorant fool and I don't comprehend many of the
items under the release note. I'm also looking for something I can
hand my boss and say ' this is why we should use postgres instead of
oracle'.

Tim