[ 
https://issues.apache.org/jira/browse/CASSANDRA-4179?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13425223#comment-13425223
 ] 

Jonathan Ellis commented on CASSANDRA-4179:
-------------------------------------------

Added 844b9c46c9ceb08a52da7738c8312e8c0b599737 to fix the build, but after that 
CliTest shows a bunch of errors that it does not prior to this.
                
> Add more general support for composites (to row key, column value)
> ------------------------------------------------------------------
>
>                 Key: CASSANDRA-4179
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4179
>             Project: Cassandra
>          Issue Type: Sub-task
>          Components: API
>            Reporter: Sylvain Lebresne
>            Assignee: Sylvain Lebresne
>            Priority: Minor
>              Labels: cql3
>             Fix For: 1.2
>
>         Attachments: 4179-2.txt, 4179.txt
>
>
> Currently CQL3 have a nice syntax for using composites in the column name 
> (it's more than that in fact, it creates a whole new abstraction but let's 
> say I'm talking implementation here). There is however 2 other place where 
> composites could be used (again implementation wise): the row key and the 
> column value. This ticket proposes to explore which of those make sense for 
> CQL3 and how.
> For the row key, I really think that CQL support makes sense. It's very 
> common (and useful) to want to stuff composite information in a row key. 
> Sharding a time serie (CASSANDRA-4176) is probably the best example but there 
> is other.
> For the column value it is less clear. CQL3 makes it very transparent and 
> convenient to store multiple related values into multiple columns so maybe 
> composites in a column value is much less needed. I do still see two cases 
> for which it could be handy:
> # to save some disk/memory space, if you do know it makes no sense to 
> insert/read two value separatly.
> # if you want to enforce that two values should not be inserted separatly. 
> I.e. to enforce a form of "constraint" to avoid programatic error.
> Those are not widely useful things, but my reasoning is that if whatever 
> syntax we come up for "grouping" row key in a composite trivially extends to 
> column values, why not support it.
> As for syntax I have 3 suggestions (that are just that, suggestions):
> # If we only care about allowing grouping for row keys:
> {noformat}
> CREATE TABLE timeline (
>     name text,
>     month int,
>     ts timestamp,
>     value text,
>     PRIMARY KEY ((name, month), ts)
> )
> {noformat}
> # A syntax that could work for both grouping in row key and colum value:
> {noformat}
> CREATE TABLE timeline (
>     name text,
>     month int,
>     ts timestamp,
>     value1 text,
>     value2 text,
>     GROUP (name, month) as key,
>     GROUP (value1, value2),
>     PRIMARY KEY (key, ts)
> )
> {noformat}
> # An alternative to the preceding one:
> {noformat}
> CREATE TABLE timeline (
>     name text,
>     month int,
>     ts timestamp,
>     value1 text,
>     value2 text,
>     GROUP (name, month) as key,
>     GROUP (value1, value2),
>     PRIMARY KEY (key, ts)
> ) WITH GROUP (name, month) AS key
>    AND GROUP (value1, value2)
> {noformat}

--
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

        

Reply via email to