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From aaron morton <aa...@thelastpickle.com>
Subject Re: Generic questions over Cassandra 1.1/1.2
Date Sun, 25 Nov 2012 20:01:50 GMT
> Now I am going to write a new application using cassandra so I started reading 
> documentation in order to "model" the new db using all the new features and not 
> reinventing the wheel.
Some resources for CQL 3, it may match your needs. If not you can still use Thrift through
your favourite client...

There have been a few articles on the DS blog http://www.datastax.com/dev/blog
A talk at the conference by Eric  http://www.datastax.com/events/cassandrasummit2012/presentations
I did a webinar about it last month http://www.datastax.com/resources/webinars/collegecredit

> 1) SCF are deprecated and I see that what it used to be a development concept 
> (use a CF and build a row name using ROW+SC name, if you want keep sorting use 
> OPP) has become a Cassandra Concept (compund key).
Yup (they have not been officially deprecated, it's just recommended that you do not use them).


> 
> SELECT * FROM ctable WHERE basekey = ?  and myvalue = ? ORDER BY extensionkey 
> DESC LIMIT 5
> I haven't been able to do it ….
That looks ok, what was the error ? 
What cassandra version and what CQL version?
 
> 2) Is Cassandra still schemaless? One thing I loved is that to create a new 
> column I didn't have to "alter" any cf before. 
> Trying CQL 3 I noticed that if I try to make an insert of a new "column" not 
> defined in schema I raised an exception. 
CQL 3 requires a schema, however altering the schema is easier. And in 1.2 will support concurrent
schema modifications. 
Thrift API is still schema less. 

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 26/11/2012, at 12:21 AM, cbertu81@libero.it wrote:

> Hi all,
> I'm in production with cassandra since version 0.6 then upgraded to 0.7 and 
> finally to 1.0.
> If I look at my schema now it's "senseless" to be on 1.0 but many things 
> changed from 0.6 ... secondary indexes, counters, expiring columns and more.
> Now I am going to write a new application using cassandra so I started reading 
> documentation in order to "model" the new db using all the new features and not 
> reinventing the wheel.
> 
> So let's start with couple of questions ... sorry if stupid :-)
> 
> 1) SCF are deprecated and I see that what it used to be a development concept 
> (use a CF and build a row name using ROW+SC name, if you want keep sorting use 
> OPP) has become a Cassandra Concept (compund key).
> Is it right? And more, can I avoid OPP when using compound keys since inside 
> partition key data are ordered on the remaining components of the primary key?
> 
> finally  I've tried to use the order by to sort data and it works -- but can I 
> use order by and where clause on a secondary index together? 
> 
> CREATE TABLE ctable (
>    basekey uuid,
>    extensionkey uuid,
>    myvalue varchar,
>    PRIMARY KEY (basekey, extensionkey)
> )
> 
> SELECT * FROM ctable WHERE basekey = ?  and myvalue = ? ORDER BY extensionkey 
> DESC LIMIT 5
> I haven't been able to do it ....
> 
> 2) Is Cassandra still schemaless? One thing I loved is that to create a new 
> column I didn't have to "alter" any cf before. 
> Trying CQL 3 I noticed that if I try to make an insert of a new "column" not 
> defined in schema I raised an exception. 
> 
> Thanks in advance for any help
> 
> Carlo
> 
> 
> 
> 


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