Mailing-List: contact user-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@cassandra.apache.org
Received-SPF: pass (athena.apache.org: domain of edlinuxguru@gmail.com
 designates 209.85.161.44 as permitted sender)
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
         :cc:content-type:content-transfer-encoding;
        b=rkdBPdlIH8BVC1KEFrAQPxdX9Eas2tBpA0q6GV78aLV3rECMIisbnM3c5ZIE8RoATz
         G8u1q9dWsHUWnE+2abXM+emQfvH1krbZPfD1mo3AAJ85vkX3PmU/mKV5rJYLtu9Nbw26
         EWzyf2FjR8odeKrXULtbURQ3JTh86Cv11LwI4=
MIME-Version: 1.0
In-Reply-To: <1298580931510-6061959.post@n2.nabble.com>
References: <1298501380608-6058238.post@n2.nabble.com>
	<3845211436698111047@unknownmsgid>
	<1298568880974-6061197.post@n2.nabble.com>
	<AANLkTi=Yb7uQ=1jkTao7EFMvZfMqqE+wKN3BoUo6eAU3@mail.gmail.com>
	<1298571537990-6061356.post@n2.nabble.com>
	<AANLkTinPCDNKk0agmK9cneYhSuDbWMxkM6XnDGYWPEgi@mail.gmail.com>
	<1298575118030-6061574.post@n2.nabble.com>
	<AANLkTinrwjLF+uWSmezdo1pF=_kMwRJWfKtjLNRvYJVe@mail.gmail.com>
	<1298579694715-6061857.post@n2.nabble.com>
	<AANLkTinGj==08SpnrOE7VQSsrezM3uVbFov0vAGHQLbU@mail.gmail.com>
	<1298580931510-6061959.post@n2.nabble.com>
Date: Thu, 24 Feb 2011 16:00:25 -0500
Message-ID: <AANLkTiksJiTXMFc=ftH_4iDX=SMSfCRBB5RM_fqSbrhW@mail.gmail.com>
Subject: Re: Understanding Indexes
From: Edward Capriolo <edlinuxguru@gmail.com>
To: user@cassandra.apache.org
Cc: mcasandra <mohitanchlia@gmail.com>, cassandra-user@incubator.apache.org
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

On Thu, Feb 24, 2011 at 3:55 PM, mcasandra <mohitanchlia@gmail.com> wrote:
>
> Either I am not explaning properly or I don't understand the data model j=
ust
> yet. Please check again:
>
> In below example this is what I understand:
>
> 1) UserProfile is a CF
> 2) 1111 is a row key
> 3) username is a column. Each row (eg 1111) has username column
>
> My understanding is that secondary indexes can be created only on column
> value. Which means I can create secondary index only on username, email e=
tc.
> not on 1111. 1111 is the row key, but you keep saying that I need seconda=
ry
> index, but I am actually asking about index on the row key.
>
> Is my understanding incorrect about this?
>
>> UserProfile =3D { // this is a ColumnFamily
>> =A0 =A01111 { =A0 // this is the key to this Row inside the CF
>> =A0 =A0 =A0 =A0// now we have an infinite # of columns in this row
>> =A0 =A0 =A0 =A0username: "phatduckk",
>> =A0 =A0 =A0 =A0email: "[hidden email]",
>> =A0 =A0 =A0 =A0phone: "(900) 976-6666"
>> =A0 =A0}, // end row
>> =A0 =A02222 { =A0 // this is the key to another row in the CF
>> =A0 =A0 =A0 =A0// now we have another infinite # of columns in this row
>> =A0 =A0 =A0 =A0username: "ieure",
>> =A0 =A0 =A0 =A0email: "[hidden email]",
>> =A0 =A0 =A0 =A0phone: "(888) 555-1212"
>> =A0 =A0 =A0 =A0age: "66",
>> =A0 =A0 =A0 =A0gender: "undecided"
>> =A0 =A0},
>> =A0}
>
> --
> View this message in context: http://cassandra-user-incubator-apache-org.=
3065146.n2.nabble.com/Understanding-Indexes-tp6058238p6061959.html
> Sent from the cassandra-user@incubator.apache.org mailing list archive at=
 Nabble.com.
>

You do not need secondary indexes to search on the RowKey. The Row Key
is used by the partitioner to locate your data across the cluster. The
Row Key is also used as the primary sort of the SSTables. Thus the row
key is naturally indexed.