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Carl Yeksigian commented on CASSANDRA-6477:
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bq. That said, as far as I can tell that's a problem even with a single column
that is not in the original PK. Yet, it's supposed to be supported by the
patch. How does it work? What happen once that column expires?
Because that is the only column which is supported, we TTL the row in the view
so that it is taken care of the same as the base TTL. The difference here would
be that there would also need to be a new value created which is the NULL that
the TTL will result in after it has expired. We would either need special logic
to handle a TTL on compaction (and lose some eventual consistency), or generate
a future timestamped value for the NULL whenever we create a TTL that will
become valid when the TTL expires on the base and view columns.
bq. That part I don't follow.
We don't have semantics for regular columns to be set null, instead that
indicates that they are tombstones. We can't distinguish between an explicitly
set NULL and one that happened because we either tombstoned the columns or we
never set the included columns, so we will have to use the NULL value for all
unset and tombstoned columns.
> 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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