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 arodrime@gmail.com designates
 209.85.215.46 as permitted sender)
MIME-Version: 1.0
In-Reply-To: 
 <CA+VSrLr9MUR7iF+ZUk=mwrVPP3E-Vpfvjr3MPhxZuO1d6i4wWQ@mail.gmail.com>
References: <20130731104703.GG1764@snowy.squish.net>
 <CA+VSrLr9MUR7iF+ZUk=mwrVPP3E-Vpfvjr3MPhxZuO1d6i4wWQ@mail.gmail.com>
From: Alain RODRIGUEZ <arodrime@gmail.com>
Date: Wed, 31 Jul 2013 14:22:51 +0200
Message-ID: 
 <CA+VSrLqw5PYE_1FKGCtkYESFO7qNDmqWcxV_DwhYB_DABTRorA@mail.gmail.com>
Subject: Re: CQL and undefined columns
To: user@cassandra.apache.org
Content-Type: multipart/alternative; boundary=089e0160bab0f374ec04e2cdc984

--089e0160bab0f374ec04e2cdc984
Content-Type: text/plain; charset=ISO-8859-1

Oops, sorry about double post.

Alain


2013/7/31 Alain RODRIGUEZ <arodrime@gmail.com>

> I like to point to this article from Sylvain, which is really well written.
>
> http://www.datastax.com/dev/blog/thrift-to-cql3
>
> It explains a lot of things and is really interesting for Cassandra users
> pre-CQL3.
>
> Actually, old dynamic columns were defined this way :
>
> CREATE TABLE test (
>   key            text,
>   column1     text,
>   value          text,
>   PRIMARY KEY (key, column1)
> ) WITH COMPACT STORAGE;
>
> This is still doable with CQL3, column1 would be your column name, value,
> the value of your column. As the primary key is composed by key + column1,
> you can add as much columns as you want.
>
> An other way to do it is to dynamically add columns (Alter table ...,
> afaik, this is lock free and does not slow performance too much).
>
>
> 2013/7/31 Jon Ribbens <jon-cassandra@unequivocal.co.uk>
>
>> I thought that part of the point of Cassandra was that, unlike a
>> standard relational database, each row does not have to have the same
>> set of columns. I don't understand how this squares with CQL. If I want
>> to have a table ("column family"?) with a few fixed columns that are
>> relevant to every row, I can create that with CQL's CREATE TABLE, but
>> if I then want to set extra columns with arbitrary names on various
>> rows, how do I tell CQL what type those columns are? Or is this
>> feature of Cassandra now deprecated?
>>
>
>

--089e0160bab0f374ec04e2cdc984
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Oops, sorry about double post.<div><br></div><div>Alain</d=
iv></div><div class=3D"gmail_extra"><br><br><div class=3D"gmail_quote">2013=
/7/31 Alain RODRIGUEZ <span dir=3D"ltr">&lt;<a href=3D"mailto:arodrime@gmai=
l.com" target=3D"_blank">arodrime@gmail.com</a>&gt;</span><br>

<blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1p=
x #ccc solid;padding-left:1ex"><div dir=3D"ltr">I like to point to this art=
icle from Sylvain, which is really well written.<div><br></div><div><a href=
=3D"http://www.datastax.com/dev/blog/thrift-to-cql3" target=3D"_blank">http=
://www.datastax.com/dev/blog/thrift-to-cql3</a><br>


</div><div><br></div><div>It explains a lot of things and is really interes=
ting for Cassandra users pre-CQL3.</div><div><br></div><div>Actually, old d=
ynamic columns were defined this way :</div><div><br></div><div><div>CREATE=
 TABLE test (</div>


<div>=A0 key =A0 =A0 =A0 =A0 =A0 =A0text,</div><div>=A0 column1 =A0 =A0 tex=
t,</div><div>=A0 value =A0 =A0 =A0 =A0 =A0text,</div><div>=A0 PRIMARY KEY (=
key,=A0column1)</div><div>) WITH COMPACT STORAGE;</div></div><div><br></div=
><div>This is still doable with CQL3, column1 would be your column name, va=
lue, the value of your column. As the primary key is composed by key + colu=
mn1, you can add as much columns as you want.=A0</div>


<div><br></div><div>An other way to do it is to dynamically add columns (Al=
ter table ..., afaik, this is lock free and does not slow performance too m=
uch).=A0</div></div><div class=3D"HOEnZb"><div class=3D"h5"><div class=3D"g=
mail_extra">

<br><br><div class=3D"gmail_quote">
2013/7/31 Jon Ribbens <span dir=3D"ltr">&lt;<a href=3D"mailto:jon-cassandra=
@unequivocal.co.uk" target=3D"_blank">jon-cassandra@unequivocal.co.uk</a>&g=
t;</span><br><blockquote class=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;b=
order-left:1px #ccc solid;padding-left:1ex">


I thought that part of the point of Cassandra was that, unlike a<br>
standard relational database, each row does not have to have the same<br>
set of columns. I don&#39;t understand how this squares with CQL. If I want=
<br>
to have a table (&quot;column family&quot;?) with a few fixed columns that =
are<br>
relevant to every row, I can create that with CQL&#39;s CREATE TABLE, but<b=
r>
if I then want to set extra columns with arbitrary names on various<br>
rows, how do I tell CQL what type those columns are? Or is this<br>
feature of Cassandra now deprecated?<br>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div>

--089e0160bab0f374ec04e2cdc984--