DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=Yahoo.com;
	h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding;
	b=gvj7go8D6iEy/pUEBk4l0W4AngnWnTdRn1Y9vdd9aq+mv2j8yQCheKyBdXM+i1BbsdQTOrDZ7llYy+68iQCc37NDFUVcyZ+XvQ7Xa1bc555y+6e7cnb1Kj0Kqhy0AuckD2Ep1o96IL0KSKLQ+uW2Z4CaAfEijRGeAxPutBTbFGQ=
	;
Message-ID: <435FAA21.3070400@Yahoo.com>
Date: Wed, 26 Oct 2005 12:09:05 -0400
From: Jan Wieck <JanWieck@Yahoo.com>
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US;
	rv:1.7.1) Gecko/20040707
MIME-Version: 1.0
To: Scott Marlowe <smarlowe@g2switchworks.com>
Cc: Kenneth Gonsalves <lawgon@thenilgiris.com>,
	PostgreSQL SQL <pgsql-sql@postgresql.org>
Subject: Re: why vacuum
References: <200510261015.17623.lawgon@thenilgiris.com>
	<1130339980.2872.12.camel@state.g2switchworks.com>
In-Reply-To: <1130339980.2872.12.camel@state.g2switchworks.com>
Content-Type: text/plain; charset=us-ascii; format=flowed
Content-Transfer-Encoding: 7bit

On 10/26/2005 11:19 AM, Scott Marlowe wrote:

> On Tue, 2005-10-25 at 23:45, Kenneth Gonsalves wrote:
>> hi,
>> i was in a minor flame war with a mysql guy - his major grouse was that 
>> 'I wouldnt commit mission critical data to a database that needs to be 
>> vacuumed once a week'. So why does pg need vacuum?
> 
> Oh man oh man.  After reading the article, I realized he was saying that
> he wouldn't trust PostgreSQL to replace Oracle.  He apparently wouldn't
> trust MySQL to replace oracle either.
> 
> But, the next time someone says that slony is a toy add on, and MySQL
> has REAL replication, point them to THIS page on the same blog:
> 
> http://ebergen.net/wordpress/?p=70
> 

You must have missed the FAQ and other side notes about replication in 
the MySQL manual. Essentially MySQL replication is nothing but a query 
duplicating system, with the added sugar of taking care of now() and 
some other non-deterministic things, but not all of them.

Non-deterministic user defined procedures, functions and triggers will 
simply blow MySQL's sophisticated replication apart.


Jan

> In short, it basically shows that MySQL replication is incredibly
> fragile, and not fit for production on any real system.  The lack of
> system wide transaction support, like postgresql has, makes the problem
> he outlines that much worse.
> 
> The hoops people will jump through to use their favorite toys...
> 
> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings


-- 
#======================================================================#
# It's easier to get forgiveness for being wrong than for being right. #
# Let's break this rule - forgive me.                                  #
#================================================== JanWieck@Yahoo.com #