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From Vladimir Prudnikov <v.prudni...@gmail.com>
Subject Re: Intresting issue with getting Order By to work...
Date Thu, 18 Jul 2013 10:54:38 GMT
I'm not an expert, still learning C* but can tell something about your
questions.

1) You have to understand that CQL row is not the same as row that C* uses
to store data and which is accessible through the Trift interface. Primary
key in terms of CQL is not the same as Row key.

2) You have to be clear what you want to order: raw columns, rows or CQL
rows. If you want to get ordered slices of raw rows you have to use Order
Preserving Partitioner (which is not recommended, depends on you schema);
If you want to order columns, it can be done easily; If you want to order
CQL rows you have to have a composite primary key with at least 2 columns
and you can order only by the second column in primary key.

3) As far as I know column families created from CLI or Thrift will be
accessible from CQL, but not opposite.

I hope experts will correct me if I'm wrong.


On 17/07/2013, at 3:44 PM, Tony Anecito <adanecito@yahoo.com> wrote:
>
> > Hi All,
> >
> > Well I got most everything working I wanted using Cassandra then
> discovered I needed to use an Order By. I am using Cassandra 1.2.5.
> > The use of Order By requires Primary Key which appears to be only
> supported by by using CQL and not Cassandra-cli. So I dropped my table
> created uisng CLI and used CQL and was able to create a "Table". But when I
> went to insert data that worked fine on the cli created table I now get an
> exception:
> > Error while inserting
> com.datastax.driver.core.exceptions.InvalidQueryException: Unknown
> identifier type.
> >
> > I read that thrift clients will not work with CQL created tables due to
> extra things created by the CQL. If so how can I create Primary Keys and be
> supported by thrift based clients??
> >
> > I will post to Datastax the same question but trying to understand how
> to resolve cli vs CQL issue like this. Seems like Cassandra-cli should
> support creation of compound primary keys or CQL should create tables
> readable by thrift based clients. Is there some meta column info people
> should add?
> > Also CQL tables are not visible via cli.so I can not see details on what
> was created by CQL and the cqlsh script has errors according to the latest
> Python windows program I tried.
> >
> > Thanks,
> > -Tony
> >
> >
>
>
>
>


-- 
Vladimir Prudnikov

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