Mailing-List: contact commits-help@cassandra.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@cassandra.apache.org
Date: Wed, 2 Mar 2016 17:33:18 +0000 (UTC)
From: "Tyler Hobbs (JIRA)" <jira@apache.org>
To: commits@cassandra.apache.org
Message-ID: <JIRA.12722816.1403282546000.196783.1456939998663@Atlassian.JIRA>
In-Reply-To: <JIRA.12722816.1403282546000@Atlassian.JIRA>
References: <JIRA.12722816.1403282546000@Atlassian.JIRA>
 <JIRA.12722816.1403282546385@arcas>
Subject: [jira] [Commented] (CASSANDRA-7423) Allow updating individual
 subfields of UDT
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit


    [ https://issues.apache.org/jira/browse/CASSANDRA-7423?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15176045#comment-15176045 ] 

Tyler Hobbs commented on CASSANDRA-7423:
----------------------------------------

That makes sense -- I'm not sure why I didn't think of that yesterday.  I've force-pushed an update to the branch that checks for non-frozen collections nested within non-frozen UDTs when creating a table.

> Allow updating individual subfields of UDT
> ------------------------------------------
>
>                 Key: CASSANDRA-7423
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7423
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: CQL
>            Reporter: Tupshin Harper
>            Assignee: Tyler Hobbs
>              Labels: client-impacting, cql, docs-impacting
>             Fix For: 3.x
>
>
> Since user defined types were implemented in CASSANDRA-5590 as blobs (you have to rewrite the entire type in order to make any modifications), they can't be safely used without LWT for any operation that wants to modify a subset of the UDT's fields by any client process that is not authoritative for the entire blob. 
> When trying to use UDTs to model complex records (particularly with nesting), this is not an exceptional circumstance, this is the totally expected normal situation. 
> The use of UDTs for anything non-trivial is harmful to either performance or consistency or both.
> edit: to clarify, i believe that most potential uses of UDTs should be considered anti-patterns until/unless we have field-level r/w access to individual elements of the UDT, with individual timestamps and standard LWW semantics


--
This message was sent by Atlassian JIRA
(v6.3.4#6332)