Return-Path: 
 <user-return-17475-apmail-cassandra-user-archive=cassandra.apache.org@cassandra.apache.org>
X-Original-To: apmail-cassandra-user-archive@www.apache.org
Delivered-To: apmail-cassandra-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 E34E547B0
	for <apmail-cassandra-user-archive@www.apache.org>;
 Wed,  8 Jun 2011 09:00:41 +0000 (UTC)
Received: (qmail 84363 invoked by uid 500); 8 Jun 2011 09:00:39 -0000
Delivered-To: apmail-cassandra-user-archive@cassandra.apache.org
Received: (qmail 84301 invoked by uid 500); 8 Jun 2011 09:00:39 -0000
Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
List-Help: <mailto:user-help@cassandra.apache.org>
List-Unsubscribe: <mailto:user-unsubscribe@cassandra.apache.org>
List-Post: <mailto:user@cassandra.apache.org>
List-Id: <user.cassandra.apache.org>
Reply-To: user@cassandra.apache.org
Delivered-To: mailing list user@cassandra.apache.org
Received: (qmail 84237 invoked by uid 99); 8 Jun 2011 09:00:39 -0000
Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 08 Jun 2011 09:00:39 +0000
X-ASF-Spam-Status: No, hits=1.5 required=5.0
	tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_LOW,RFC_ABUSE_POST,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: apache.org
Received-SPF: pass (athena.apache.org: domain of pdetorcy@gmail.com designates
 209.85.216.44 as permitted sender)
Received: from [209.85.216.44] (HELO mail-qw0-f44.google.com) (209.85.216.44)
    by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 08 Jun 2011 09:00:32 +0000
Received: by qwc23 with SMTP id 23so177031qwc.31
        for <user@cassandra.apache.org>; Wed, 08 Jun 2011 02:00:12 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
        d=gmail.com; s=gamma;
        h=domainkey-signature:mime-version:in-reply-to:references:date
         :message-id:subject:from:to:content-type;
        bh=7rh1GaxqJQZ0n+uoUi851KXK7Boh69Ie+Qqqk1tEqzU=;
        b=aoL4WOdo8n5VlKvawQBRsDdJYISmWoG9m9BPFUeMMh+J6v/UoTN0cWBijzj+nLTDVA
         L5rJhnPFhpmqTstg9UXKAqT4Pg+FubO+bXyD2dRpRDbbJzZ8+tLNddvh+GUmtSw7OB2z
         uTMGHDN3mG512bOzvIRihMKJDmuXaSiLsUEhg=
DomainKey-Signature: a=rsa-sha1; c=nofws;
        d=gmail.com; s=gamma;
        h=mime-version:in-reply-to:references:date:message-id:subject:from:to
         :content-type;
        b=BgnI1G4OVepxHkL2DF3UyIoNA8KHWz5BCWwqLOuLW7hq3Y5bqUOX7Zni7QjckXSuCk
         Idq7D0VqTlUvcm50ILU+D9/DQRqx9cHdlmp1FjOKNgiTqdzwcbs41vP373/iKRbhS77G
         HWZItADLkfWv0cbLQL3Q/g5CC+sC7vYmu5Ub8=
MIME-Version: 1.0
Received: by 10.229.106.69 with SMTP id w5mr5448028qco.41.1307523612031; Wed,
 08 Jun 2011 02:00:12 -0700 (PDT)
Received: by 10.229.112.30 with HTTP; Wed, 8 Jun 2011 02:00:11 -0700 (PDT)
In-Reply-To: <C3FF2A95-A30F-45D7-B624-614835EB2672@thelastpickle.com>
References: <551354.92754.qm@web110405.mail.gq1.yahoo.com>
	<BANLkTi=uPqpUHSM8tti+Ap+QXq+T5G8xBw@mail.gmail.com>
	<BANLkTi=JR7A4_GxS0jmwZ6qn3F=UP7QciA@mail.gmail.com>
	<ACDD8251-5653-4346-97FB-02C4657880D3@thelastpickle.com>
	<BANLkTinM_eE2gCXBq3G58EqjCWiXxi8hCg@mail.gmail.com>
	<C3FF2A95-A30F-45D7-B624-614835EB2672@thelastpickle.com>
Date: Wed, 8 Jun 2011 11:00:11 +0200
Message-ID: <BANLkTikBkSgwu8wsmTM9zgnXuSmKY_KnUA@mail.gmail.com>
Subject: Re: how to know there are some columns in a row
From: Patrick de Torcy <pdetorcy@gmail.com>
To: user@cassandra.apache.org
Content-Type: multipart/alternative; boundary=0023544719cc6e3c4c04a52f90ab

--0023544719cc6e3c4c04a52f90ab
Content-Type: text/plain; charset=ISO-8859-1

There is no reason for ambiguities...
We could add in the api another method call (similar to get_count) :

get_columnNames

   -

   list<string>
   get_columnNames(key, column_parent, predicate, consistency_level)

Get the columns names present in column_parent within the predicate.

The method is not O(1). It takes all the columns from disk to calculate the
answer. The only benefit of the method is that you do not need to pull all
their values over Thrift interface to get their names

(just to get the idea...)

In fact column names can really be data in themselves, so there should be a
way to retrieve them (without their values). When you have big values, it's
a real show stopper to use get_slice, since a lot of unnecessary traffic
would be generated...

Forgive me if I am a little insistent, but it's important for us and I'm
sure we are not the only ones interested in this feature...

cheers

--0023544719cc6e3c4c04a52f90ab
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

There is no reason for ambiguities...<br>We could add in the api another me=
thod call (similar to get_count) :<br><span style=3D"display: block; paddin=
g-left: 6em;"><span></span></span><br><h3 id=3D"get_count">get_columnNames<=
/h3>

<span class=3D"anchor" id=3D"line-243"></span><ul><li style=3D"list-style-t=
ype: none;"><p class=3D"line862"><tt class=3D"backtick">list&lt;string&gt; =
get_columnNames(key,=A0column_parent,=A0predicate,=A0consistency_level)</tt=
> <span class=3D"anchor" id=3D"line-244"></span><span class=3D"anchor" id=
=3D"line-245"></span></p>
</li></ul><p class=3D"line874">Get the columns names present in <tt class=
=3D"backtick">column_parent</tt> within the <tt class=3D"backtick">predicat=
e.</tt> <span class=3D"anchor" id=3D"line-246"></span><span class=3D"anchor=
" id=3D"line-247"></span></p>
<p class=3D"line874">The
 method is not O(1). It takes all the columns from disk to calculate the
 answer. The only benefit of the method is that you do not need to pull=20
all their values over Thrift interface to get their names<br></p><br>(just =
to get the idea...)<br><br>In fact column names can really be data in thems=
elves, so there should be a way to retrieve them (without their values). Wh=
en you have big values, it&#39;s a real show stopper to use get_slice, sinc=
e a lot of unnecessary traffic would be generated...<br>
<br>Forgive me if I am a little insistent, but it&#39;s important for us an=
d I&#39;m sure we are not the only ones interested in this feature...<br><b=
r>cheers<br>

--0023544719cc6e3c4c04a52f90ab--