[ 
https://issues.apache.org/jira/browse/CASSANDRA-1311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12975280#action_12975280
 ] 

Jonathan Ellis commented on CASSANDRA-1311:
-------------------------------------------

i take it this is best-suited for triggers that are

- invoked frequently
- idempotent

so that missing an update once in a while (because of a server restart after 
row update but before trigger processing) is not a big deal?

what use cases do we have for this?  indexing actually does not fit this 
description, since if you miss updating an index row for changing the value 
from 4 to 6, firing the trigger for the change from 6 to 8 will not fix the 
invalid index entry for 4.

> Support (asynchronous) triggers
> -------------------------------
>
>                 Key: CASSANDRA-1311
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-1311
>             Project: Cassandra
>          Issue Type: New Feature
>          Components: Contrib
>            Reporter: Maxim Grinev
>             Fix For: 0.8
>
>         Attachments: HOWTO-PatchAndRunTriggerExample-update1.txt, 
> HOWTO-PatchAndRunTriggerExample.txt, ImplementationDetails-update1.pdf, 
> ImplementationDetails.pdf, trunk-967053.txt, trunk-984391-update1.txt, 
> trunk-984391-update2.txt
>
>
> Asynchronous triggers is a basic mechanism to implement various use cases of 
> asynchronous execution of application code at database side. For example to 
> support indexes and materialized views, online analytics, push-based data 
> propagation.
> Please find the motivation, triggers description and list of applications:
> http://maxgrinev.com/2010/07/23/extending-cassandra-with-asynchronous-triggers/
> An example of using triggers for indexing:
> http://maxgrinev.com/2010/07/23/managing-indexes-in-cassandra-using-async-triggers/
> Implementation details are attached.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to