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https://issues.apache.org/jira/browse/CASSANDRA-1311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12998226#comment-12998226
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Stu Hood commented on CASSANDRA-1311:
-------------------------------------
I believe that the entity group functionality can actually be implemented as
sugar on top of our existing secondary indexes and column nesting (I'll
describe what I'm thinking of on that ticket).
This ticket, on the other hand, provides novel functionality, so my vote is
strongly in favor of getting it in mostly-as-is, with slight adjustments:
* ITriggers should be configured to match a filter, as described on
CASSANDRA-1601. Rather than triggering for any change to a row, it should
trigger for changes to a set of names, or a slice of names. For example:
setting a trigger for columns 'age' and 'state' would only fire the trigger if
either of those columns changed
* The ITrigger contract should not guarantee to give the user all changed
columns: only the columns matching the trigger configuration.
I'm hoping that in future tickets we can unify these ''at-least-once''
distributed triggers with our ''exactly-once'' local indexes (with UDFs) around
common configuration: see CASSANDRA-1601.
> 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.
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