Re: MySQL transactional support?

On Sunday 07 July 2002 04:23 pm, Justin Erenkrantz wrote:
> On Sun, Jul 07, 2002 at 10:29:02AM -0400, Mark C. Chu-Carroll wrote:
> > It's a bit funny to me watching this discussion this weekend. Stellation
> > was released open-source last thursday. By thursday afternoon, we had
> > our first request/volunteer for adding MySQL support. So we've been
> > having
>
> I know in my conversations with Dave Shields, he mentioned that
> MySQL didn't support transactions properly. Therefore, MySQL can
> not be used by anyone looking for a consistent DB. Or, have recent
> MySQL databases improved their robustness?

We looked at MySQL about a year ago, and at the time, transactional
tables had been added, but there was no way to wrap a collection
of statements into a single transaction. For Stellation, we need the
ability to properly handle long transactions, because our checkins
are a single transaction.

One of the first messages we got after we released the code last week
pointed us at the InnoDB extensions to MySQL, which add long-transaction
support. With InnoDB, MySQL can be used as a full ACID RDB.

> Regardless of the licensing debates, if that is still the case,
> that alone should make Subversion not use MySQL. Subversion is
> going to require solid transactional support on the backend. If
> MySQL is going to open the door for inconsistencies, then we must
> not support it.

With InnoDB, that's no longer the case. Single SQL statements are
all fully transactional, and there's a form of SQL support for long
transactions.

> In point of opinion, I believe MySQL is nightmare to work with and
> its (write) performance is awful. If we are going to support any SQL
> DB, IMHO, MySQL should not be our preference. -- justin

I haven't worked with it at all. InnoDB has some *very* impressive
performance numbers. But since we haven't put support for it
into Stellation (yet), I can't say how it works in practice.

        -Mark

-- 
Mark Craig Chu-Carroll,  IBM T.J. Watson Research Center  
*** The Stellation project: Advanced SCM for Collaboration
***		http://www.eclipse.org/stellation
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