[
https://issues.apache.org/jira/browse/CASSANDRA-6382?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13827685#comment-13827685
]
Sylvain Lebresne commented on CASSANDRA-6382:
---------------------------------------------
As said on CASSANDRA-4511, there is no real technical challenge on the indexing
part here (unless there's one I miss), but I'm not at all sure about what
syntax to go with. The difficulty being that, because user types are mostly
useful inside collections, we'd want to allow indexing a specific field of the
value of a collection. To make things concrete, if we have the following table:
{noformat}
CREATE TYPE pair (x int, y int);
CREATE TABLE test (
k int PRIMARY KEY,
s set<pair>
);
{noformat}
We'd want to index the 'y' field of the values of 's'.
And there is 2 bits for which we need a syntax: 1) to declare the index in the
first place and 2) to actually query it.
For 1), I might suggest something like:
{noformat}
CREATE INDEX ON test(values(s).y);
{noformat}
and we would have a keys() pseudo-function for maps too, which could be the
syntax we use for CASSANDRA-6383 (in which case, {{CREATE INDEX ON test(s)}}
would basically be a shortcut for {{CREATE INDEX ON test(values(s))}}).
For 2), I don't have any good idea so far, outside of my suggestion from
CASSANDRA-4511, i.e:
{noformat}
SELECT * FROM bar WHERE $e.y = 'foo' FOR $e IN s;
{noformat}
but that a tad complex maybe.
> Allow indexing nested types
> ---------------------------
>
> Key: CASSANDRA-6382
> URL: https://issues.apache.org/jira/browse/CASSANDRA-6382
> Project: Cassandra
> Issue Type: New Feature
> Components: API, Core
> Reporter: Jonathan Ellis
> Assignee: Sylvain Lebresne
> Fix For: 2.1
>
>
--
This message was sent by Atlassian JIRA
(v6.1#6144)
