You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "Christoph Tavan (JIRA)" <ji...@apache.org> on 2012/06/04 10:28:23 UTC

[jira] [Commented] (CASSANDRA-4176) Support for sharding wide rows in CQL 3.0

    [ https://issues.apache.org/jira/browse/CASSANDRA-4176?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13288413#comment-13288413 ] 

Christoph Tavan commented on CASSANDRA-4176:
--------------------------------------------

I think the suggestion to discuss sharding and composite row keys/values in a different issue is good.

If we wanna have event more specific/dedicated support for sharding, a different syntax idea for (borrowed from [MySQL|http://dev.mysql.com/doc/refman/5.1/en/create-table.html]) might be:

{code}
CREATE TABLE timeline (
    user_id varchar,
    tweet_id uuid,
    author varchar,
    body varchar,
    PRIMARY KEY (user_id, tweet_id)
) PARTITION BY HASH(user_id, DAY(tweet_id)) PARTITIONS 10;
{code}

It would read very straightforward IMO, but maybe that's already too high-level? 
                
> Support for sharding wide rows in CQL 3.0
> -----------------------------------------
>
>                 Key: CASSANDRA-4176
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4176
>             Project: Cassandra
>          Issue Type: Sub-task
>          Components: API
>            Reporter: Nick Bailey
>             Fix For: 1.1.2
>
>
> CQL 3.0 currently has support for defining wide rows by declaring a composite primary key. For example:
> {noformat}
> CREATE TABLE timeline (
>     user_id varchar,
>     tweet_id uuid,
>     author varchar,
>     body varchar,
>     PRIMARY KEY (user_id, tweet_id)
> );
> {noformat}
> It would also be useful to manage sharding a wide row through the cql schema. This would require being able to split up the actual row key in the schema definition. In the above example you might want to make the row key a combination of user_id and day_of_tweet, in order to shard timelines by day. This might look something like:
> {noformat}
> CREATE TABLE timeline (
>     user_id varchar,
>     day_of_tweet date,
>     tweet_id uuid,
>     author varchar,
>     body varchar,
>     PRIMARY KEY (user_id REQUIRED, day_of_tweet REQUIRED, tweet_id)
> );
> {noformat}
> Thats probably a terrible attempt at how to structure that in CQL. But I think I've gotten the point across. I tagged this for cql 3.0, but I'm honestly not sure how much work it might be. As far as I know built in support for composite keys is limited.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira