[
https://issues.apache.org/jira/browse/CASSANDRA-6477?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14363846#comment-14363846
]
Jonathan Ellis commented on CASSANDRA-6477:
-------------------------------------------
On the one hand, all queries that would be valid w/o GI should still be valid
-- with similar caveats to 2i, i.e., filtering on 2 GI columns won't actually
be faster than 1 GI and 1 non-indexed-but-included column, until we have actual
multi-column indexes.
On the other hand, GI introduces a new way to introduce a query that is much
slower than expected -- if you filter on a column that is not included in the
GI, then you need to fall back to seq scan on the base table.
> 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
>
>
> 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.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
