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From "James Taylor (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (PHOENIX-953) Support UNNEST for ARRAY
Date Wed, 12 Aug 2015 20:07:46 GMT

    [ https://issues.apache.org/jira/browse/PHOENIX-953?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14694085#comment-14694085
] 

James Taylor commented on PHOENIX-953:
--------------------------------------

We wouldn't want the Cartesian product, we'd want the first elements from each array as row
1, the second element from each array as row 2, etc. It's common to have parallel arrays that
you'd want to UNNEST this way (that's how I've seen it implemented in some DBs). Is there
an alternate syntax to accomplish this, [~julianhyde]?

> Support UNNEST for ARRAY
> ------------------------
>
>                 Key: PHOENIX-953
>                 URL: https://issues.apache.org/jira/browse/PHOENIX-953
>             Project: Phoenix
>          Issue Type: Sub-task
>            Reporter: James Taylor
>            Assignee: Dumindu Buddhika
>         Attachments: PHOENIX-953-v1.patch
>
>
> The UNNEST built-in function converts an array into a set of rows. This is more than
a built-in function, so should be considered an advanced project.
> For an example, see the following Postgres documentation: http://www.postgresql.org/docs/8.4/static/functions-array.html
> http://www.anicehumble.com/2011/07/postgresql-unnest-function-do-many.html
> http://tech.valgog.com/2010/05/merging-and-manipulating-arrays-in.html
> So the UNNEST is a way of converting an array to a flattened "table" which can then be
filtered on, ordered, grouped, etc.



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