Extract meta-data using cql 3

[Murali <mu...@gmail.com>]

Hi experts,

How to extract meta-data of a table or a keyspace using CQL 3.0?

-- 
Thanks,
Murali

Re: Extract meta-data using cql 3

[Sylvain Lebresne <sy...@datastax.com>]

The "raw" answer is that you should query the system tables. The schema is
stored in the 3 following tables: System.schema_keyspaces,
System.schema_columnfamilies and System.schema_columns. Unfortunately, the
information stored in there is, for different reasons, not in a form that
makes
a lot of sense from a CQL3 point of view.

So in practice, you should probably rely on your client drivers that might
provide that same information but in a more usable way. For instance, with
cqlsh, you have a DESCRIBE command. Of if you say use the DataStax Java
driver,
you can access all those metadata through
cluster.getMetadata().getKeyspaces(),
etc...



On Fri, Jul 12, 2013 at 10:52 AM, Murali <mu...@gmail.com> wrote:

> Hi experts,
>
> How to extract meta-data of a table or a keyspace using CQL 3.0?
>
> --
> Thanks,
> Murali
>
>

Re: Extract meta-data using cql 3

[Theo Hultberg <th...@iconara.net>]

there's a keyspace called system which has a few tables that contain the
metadata. for example schema_keyspaces that contain keyspace metadata, and
schema_columnfamilies that contain table metadata. there are more, just
fire up cqlsh and do a describe keyspace in the system keyspace to find
them.

T#


On Fri, Jul 12, 2013 at 10:52 AM, Murali <mu...@gmail.com> wrote:

> Hi experts,
>
> How to extract meta-data of a table or a keyspace using CQL 3.0?
>
> --
> Thanks,
> Murali
>
>