Re: What X86/X64 OS's do we need coverage for?

On Fri, 6 Apr 2007, Matthew O'Connor wrote:

> Devrim Gndz wrote:
>> Hi,
>> 
>> On Fri, 2007-04-06 at 01:23 -0400, Matthew T. O'Connor wrote:
>>> The other thing to consider is that CentOS 5 has Xen built right in,
>>> so you should be able run VMs without VMWare on it. 
>> 
>> ... if the kernel of the OS has Xen support, there will be no
>> performance penalty (only 2%-3%) (Para-virtualization). Otherwise, there
>> will be full-virtualization, and we should expect a performance loss
>> about 30% for each guest OS (like Windows).
>
> I may be wrong but I thought that the guest OS kernel only needs special 
> support if the underlying CPU doesn't have virtualization support which 
> pretty much all the new Intel and AMD chips have.  No?
>
It doesn't matter as far as MY box is concerned.  I use VMWare extensively
in my current $DAYJOB, and I want to be able to test/play with things related
to that as well.  The box I'm building will be using the (free) VMWare Server
as it's virtualization platform.

I'd still like to hear from a Tom Lane or someone else on the project with what
X86 or X86_64 OS's we need coverage for.

LER

> ---------------------------(end of broadcast)---------------------------
> TIP 5: don't forget to increase your free space map settings
>

-- 
Larry Rosenman                     http://www.lerctr.org/~ler
Phone: +1 512-248-2683                 E-Mail: ler@lerctr.org
US Mail: 430 Valona Loop, Round Rock, TX 78681-3893
>From pgsql-hackers-owner@postgresql.org  Fri Apr  6 11:09:32 2007
Received: from localhost (maia-3.hub.org [200.46.204.184])
	by postgresql.org (Postfix) with ESMTP id 3870A9FB47A
	for <pgsql-hackers-postgresql.org@postgresql.org>; Fri,  6 Apr 2007 11:09:31 -0300 (ADT)
Received: from postgresql.org ([200.46.204.71])
 by localhost (mx1.hub.org [200.46.204.184]) (amavisd-maia, port 10024)
 with ESMTP id 12956-02 for <pgsql-hackers-postgresql.org@postgresql.org>;
 Fri,  6 Apr 2007 11:09:17 -0300 (ADT)
X-Greylist: from auto-whitelisted by SQLgrey-1.7.4
Received: from nabagan.bluegap.ch (nabagan.bluegap.ch [88.198.58.248])
	by postgresql.org (Postfix) with ESMTP id 8EBA59FB542
	for <pgsql-hackers@postgresql.org>; Fri,  6 Apr 2007 11:09:04 -0300 (ADT)
Received: from [192.168.77.28] (p54bd9cdd.dip0.t-ipconnect.de [::ffff:84.189.156.221])
  (AUTH: CRAM-MD5 markus@bluegap.ch, SSL: TLSv1/SSLv3,256bits,AES256-SHA)
  by nabagan.bluegap.ch with esmtp; Fri, 06 Apr 2007 17:08:19 +0200
  id 0023735E.46166264.00003A6D
Message-ID: <46165475.5070009@bluegap.ch>
Date: Fri, 06 Apr 2007 16:08:53 +0200
From: Markus Schiltknecht <markus@bluegap.ch>
User-Agent: Icedove 1.5.0.10 (X11/20070307)
MIME-Version: 1.0
To: Simon Riggs <simon@2ndquadrant.com>
CC: Zeugswetter Andreas ADI SD <ZeugswetterA@spardat.at>,
  Tom Lane <tgl@sss.pgh.pa.us>,
  Martijn van Oosterhout <kleptog@svana.org>,
  "Joshua D. Drake" <jd@commandprompt.com>,
  Gregory Stark <stark@enterprisedb.com>, NikhilS <nikkhils@gmail.com>,
  pgsql-hackers@postgresql.org
Subject: Re: Auto Partitioning
References: <d3c4af540704030836o242c49cl2688ab4ec9808ac3@mail.gmail.com> <46139825.6080204@bluegap.ch> <1175694172.3623.120.camel@silverbirch.site> <87648ckzi0.fsf@oxford.xeocode.com> <4613BB72.1090602@bluegap.ch> <871wj0ko91.fsf@oxford.xeocode.com> <4613F49E.1030901@bluegap.ch> <1175713305.3623.197.camel@silverbirch.site> <4613F809.2010607@commandprompt.com> <4613FDAB.6080501@bluegap.ch> <20070405081029.GA17587@svana.org> <46155565.2010605@bluegap.ch> <28487.1175838996@sss.pgh.pa.us> <1175843479.3623.463.camel@silverbirch.site> <E1539E0ED7043848906A8FF995BDA57901E7B93D@m0143.s-mxs.net> <1175864959.3623.497.camel@silverbirch.site>
In-Reply-To: <1175864959.3623.497.camel@silverbirch.site>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-Virus-Scanned: Maia Mailguard 1.0.1
X-Archive-Number: 200704/317
X-Sequence-Number: 101650

Simon Riggs wrote:
> i.e. if we have partitions for each year (2001, 2002, 2003 2004, 2005,
> 2006, 2007) AND we have already proved that 2005 is excluded when we
> have a WHERE clause saying year >= 2006, then we should be able to use
> the ordering to prove that partitions for 2004 and before are also
> automatically excluded.

Provided you've set up the right constraints, the current 
constraint_exclusion feature does exactly that, no?

> I'll think some more about the Merge node, but not right now.

I've looked at nodeAppend.c and nodeMergeJoin.c. Probably we can use 
much of nodeMergeJoin, just without the join? Instead returning the 
tuples as they are, but in the correct order. The nodeMergeJoin code can 
only handle two inputs (a left and a right node), but it might be 
beneficial to structure multiple merge nodes into a binary tree layout 
anyway. (I'm guessing that might reduce the amount of comparisons needed).

What do you think?

Regards

Markus