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https://issues.apache.org/jira/browse/CASSANDRA-1311?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12898378#action_12898378
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Stu Hood commented on CASSANDRA-1311:
-------------------------------------
An interesting benefit provided by CASSANDRA-1016 is that it has a
pre-execution step, allowing the Plugin/Trigger to perform a read if it needs
to (for example, to update a compound index which the mutation does not contain
all columns for).
Since making the read-then-write step atomic is out of the question, the
benefit is questionable (something I think we missed when we were considering
1016). Requiring the user to use mutations containing all fields the trigger
might need may be reasonable. Example: for updating the zipcode in an index of
"country-zipcode", it would be up to the user to include both fields in the
mutation, meaning that they might have to perform a read from their base data
first.
> 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
>
>
> 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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