mysqldump isn't a hot backup, it causes locks table and/or row (i cant remember off hand which). There is a myisamhotbackup or something like that for MyISAM tables (why the hell would you use MyISAM?), but for a real table you need the innodb hot backup thing that is commercial, and not cheap.
Also, MySQL replication isn't as trivial as you've made it sound in previous posts. A simple master->slave setup is pretty easy, but once you get into more complex setups its definitely not easy. Also, even the master->slave type replication is by no means perfectly reliable, we have to run scripts to keep slaves sync'd with the master as we've had problems with inserts not making it into the slave.
Personally, I wish we were using PG at work, but then when it was tried (years ago, before my time) it was found to be slow. Of course, in talking to the principals there, it became clear the box was memory limited, and not tuned at all.
PG requires far more tuning than MySQL does. I still like it better though.
On Wed, Dec 3, 2008 at 3:09 PM, Charles Jones
<charles.jones@ciscolearning.org> wrote:
kitepilot@kitepilot.com wrote:
> The final single reason why I went Postgres was backups.
> Back in the day when I did my research (this may have changed) you could not
> take a hot backup in MySQL without purchasing a commercial product, as
> opposite as Postgres that you can simply hot-backup a fully consistent
> database with pgdump.
>
man mysqldump :-)