Re: PostgreSQL vs. MySQL

On Aug 1, 2005, at 4:33 PM, Robert Treat wrote:

> On Monday 01 August 2005 13:52, Scott Marlowe wrote:
>
>> On Mon, 2005-08-01 at 11:44, Vratislav_Morkus(at)lmc(dot)cz wrote:
>>
>>> Hi all,
>>> I am sorry for a stupid easy question, but I'am PostgreSQL novice.
>>> Our development team has encountered problem with trying to
>>> install and
>>> maintain cluster (pgcluster) on our production database. So they
>>> have
>>> decided to switch the entire solution to MySql database.
>>> a) have you got any good/bad experience with administering and
>>> running
>>> cluster on PostrgeSQL DB?
>>> b) would u switch PostgreSQL to MySql (7.4 --> 4.1) and why?
>>>
>>
>> I would never switch from pgsql to mysql.
>>
>> Here's a short list of the reasons why:
>>
>> http://sql-info.de/mysql/gotchas.html
>>
>> If they're having problems and haven't asked for help in these lists,
>> then I'm willing to be they're just looking for an excuse to
>> change to
>> what they're comfortable with, and not really serious about using
>> postgresql.
>>
--snip--
> Can someone point me to the multi-master replication docs for my$ql
> 4.1? I
> agree with Scott, sounds like they are looking for an excuse.
>

I don't believe mysql 4.1 has multi-master replication. At least not
open sourced. If you find them, I'd be interested in reading/learning
about it.

I believe Mysql 5.0 will have a multi-master storage engine. But, it
will have a lot of gotchas too. For one, it's all in memory, so be
prepared to have several machines with lots and lots of RAM. The
Mysql docs for 5.0 cover it quite well. Watch out for its
wastefulness though. It does things like reserve space based on the
max size of a field, so if you have a varchar(250), then every row in
the database will have 250 bytes of space allocated, even if you only
use 1. At least, that's how it was documented the last time I looked
at it.

I had to rule out the mysql cluster for a project I'm working on due
to how some things are implemented.