Return-Path: X-Original-To: apmail-accumulo-user-archive@www.apache.org Delivered-To: apmail-accumulo-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 8C9F2D541 for ; Wed, 12 Sep 2012 21:27:37 +0000 (UTC) Received: (qmail 36307 invoked by uid 500); 12 Sep 2012 21:27:37 -0000 Delivered-To: apmail-accumulo-user-archive@accumulo.apache.org Received: (qmail 36271 invoked by uid 500); 12 Sep 2012 21:27:37 -0000 Mailing-List: contact user-help@accumulo.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: user@accumulo.apache.org Delivered-To: mailing list user@accumulo.apache.org Received: (qmail 36260 invoked by uid 99); 12 Sep 2012 21:27:37 -0000 Received: from minotaur.apache.org (HELO minotaur.apache.org) (140.211.11.9) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 12 Sep 2012 21:27:37 +0000 Received: from localhost (HELO mail-pb0-f41.google.com) (127.0.0.1) (smtp-auth username afuchs, mechanism plain) by minotaur.apache.org (qpsmtpd/0.29) with ESMTP; Wed, 12 Sep 2012 21:27:36 +0000 Received: by pbbro12 with SMTP id ro12so3353838pbb.0 for ; Wed, 12 Sep 2012 14:27:36 -0700 (PDT) MIME-Version: 1.0 Received: by 10.68.226.130 with SMTP id rs2mr668264pbc.151.1347485256438; Wed, 12 Sep 2012 14:27:36 -0700 (PDT) Received: by 10.68.196.165 with HTTP; Wed, 12 Sep 2012 14:27:36 -0700 (PDT) Received: by 10.68.196.165 with HTTP; Wed, 12 Sep 2012 14:27:36 -0700 (PDT) In-Reply-To: References: <7B6B9A998E54184F9E0CEED43DD504090391DDD7@0905-its-exmp01.us.saic.com> <7B6B9A998E54184F9E0CEED43DD504090391E2C2@0905-its-exmp01.us.saic.com> Date: Wed, 12 Sep 2012 17:27:36 -0400 Message-ID: Subject: Re: Running Accumulo straight from Memory From: Adam Fuchs To: user@accumulo.apache.org Content-Type: multipart/alternative; boundary=047d7b338ee50cd19a04c987dca4 --047d7b338ee50cd19a04c987dca4 Content-Type: text/plain; charset=ISO-8859-1 Yes, the effect of locality groups would be about the same in an in memory system. The only exception would be if you're not using locality groups and are fetching a particular column, the automatic seeking behavior of the column filtering iterator would be more efficient with in memory rfiles. Adam On Sep 12, 2012 5:20 PM, "David Medinets" wrote: > Why would locality groups be useful in an in-memory system? > > On Wed, Sep 12, 2012 at 4:53 PM, Adam Fuchs wrote: > > Even if you are just using memory, minor and major compactions are > important > > to get compression, handle deletes, get sequential access (cache line > > efficiency), use iterators, and introduce locality groups. > --047d7b338ee50cd19a04c987dca4 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable

Yes, the effect of locality groups would be about the same in an in memo= ry system. The only exception would be if you're not using locality gro= ups and are fetching a particular column, the automatic seeking behavior of= the column filtering iterator would be more efficient with in memory rfile= s.

Adam

On Sep 12, 2012 5:20 PM, "David Medinets&qu= ot; <david.medinets@gmail.co= m> wrote:
Why would locality groups be useful in an in-memory system?

On Wed, Sep 12, 2012 at 4:53 PM, Adam Fuchs <afuchs@apache.org> wrote:
> Even if you are just using memory, minor and major compactions are imp= ortant
> to get compression, handle deletes, get sequential access (cache line<= br> > efficiency), use iterators, and introduce locality groups.
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