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https://issues.apache.org/jira/browse/CASSANDRA-6477?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14631996#comment-14631996
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Benedict commented on CASSANDRA-6477:
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bq. As well, it does add potentially another hop,
No, it removes a hop. Several hops: Currently we write to the batch log
synchronously before we do anything else. In fact we do it twice. These are all
double-hops. I'm proposing removing all of them, by exploiting the fact that
typically the coordinator is an owner, and so as soon as two owners have the
mutations in their local batch logs we're about as good as we'll get that these
mutations _will_ be applied, and if they _aren't_ going to be applied they also
won't partially apply.
To make a more general statement: I think there is perhaps a failure to
appreciate the difficulty of the problem Sylvain was raising, around ensuring
we do not end up with a corrupted MV that we have no idea how to repair. In
fact, I very much doubt we are going to achieve this no matter how hard we try,
and this is going to end up making us look pretty bad. If a user fails to keep
their views in sync, that's one thing, but if we do it's another. I'm talking
about even _eventually_ consistent here. There are a lot of nook and cranny
failure scenarios and that's before we consider repair. Which, as I say, I
suspect completely ruins us. Ironically, of course :)
> Materialized Views (was: Global Indexes)
> ----------------------------------------
>
> Key: CASSANDRA-6477
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6477
> Project: Cassandra
> Issue Type: New Feature
> Components: API, Core
> Reporter: Jonathan Ellis
> Assignee: Carl Yeksigian
> Labels: cql
> Fix For: 3.0 beta 1
>
> Attachments: test-view-data.sh, users.yaml
>
>
> Local indexes are suitable for low-cardinality data, where spreading the
> index across the cluster is a Good Thing. However, for high-cardinality
> data, local indexes require querying most nodes in the cluster even if only a
> handful of rows is returned.
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