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From Alain RODRIGUEZ <arodr...@gmail.com>
Subject Re: CQL and undefined columns
Date Wed, 31 Jul 2013 12:22:51 GMT
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?
>>
>
>

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