Re: Performance (was: The New Slashdot Setup (includes MySql server))

Hi,

Bruce Momjian:
> > 
> > > 2. atomic_updates = no
> > That's a misnomer. They actually mean this:
> > 
> >     create table crash_q (a integer not null);
> >     create unique index crf on crash_q(a);
> > 
> >     insert into crash_q values (2);
> >     insert into crash_q values (3);
> >     insert into crash_q values (1);
> >     update crash_q set a=a+1;
> 
> Poorly named, huh?  How do you think it got such a name?  This item was
> on the crashme tests before TRANSACTION was on there?

It probably got that name because nobody thought about people
associating atomicity with transactions.

Anyway, the issue isn't all that exotic. ms-sql, mimer, db2, solid and
sybase are listed as supporting this kind of update.


If you can think of an understandable five-word-or-so description for
it, I'll happily rename the test. I've been thinking about it for the
last ten minutes or so, but couldn't come up with one. :-/


A different question is whether the database bungles the update when the
first few row can be updated and THEN you run into a conflict.

PostgreSQL handles this case correctly, MySQL doesn't => I'll add a
test for it.

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Matthias Urlichs  |  noris network GmbH   |   smurf@noris.de  |  ICQ: 20193661
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