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https://issues.apache.org/jira/browse/PHOENIX-1772?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14383006#comment-14383006
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James Taylor commented on PHOENIX-1772:
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Welcome, [~jayapriya90]. Looking forward to your contributions. Just curious -
what's the most common use case for CUBE and ROLLUP?
> Add CUBE/ROLLUP/GROUPING SET operators for advanced aggregations
> ----------------------------------------------------------------
>
> Key: PHOENIX-1772
> URL: https://issues.apache.org/jira/browse/PHOENIX-1772
> Project: Phoenix
> Issue Type: New Feature
> Reporter: jayapriya surendran
> Assignee: jayapriya surendran
> Labels: gsoc2015, java, sql
>
> I noticed from Phoenix language documentation (
> http://phoenix.apache.org/language/index.html ) that Phoenix is missing
> CUBE/ROLLUP and GROUPING_SET operators which are already supported by other
> similar projects like Apache Pig and Apache Hive. Here is brief overview of
> my proposal (the syntax that is proposed below is same as PostgreSQL
> https://wiki.postgresql.org/wiki/Grouping_Sets)
> *Proposed syntax for CUBE:*
> SELECT name, place, SUM(count) FROM cars GROUP BY CUBE(name, place);
> For every row that we process we need to emit 2^n combinations of rows where
> n corresponds to number of aggregate columns. For the above example query,
> for every row we need to emit 4 rows, one for each level of aggregations
> {(name, place), (name, *), (*, place), (*, *)}.
> *Proposed syntax for ROLLUP:*
> SELECT name, place, SUM(count) FROM cars GROUP BY ROLLUP(name, place);
> For every row that we process we need to emit n+1 combinations of rows where
> n corresponds to number of aggregate columns. For the above example query,
> for every row we need to emit 3 rows, one for each hierarchical level of
> aggregations {(name, place), (name, *), (*, *)}.
> *Propose syntax for GROUPING_SETS:*
> SELECT name, place, SUM(count) FROM cars GROUP BY GROUPING SETS(name, ());
> For every row that we process we need to emit n combinations of rows where n
> corresponds to size of grouping set. For the above example query, for every
> row we need to emit 2 rows, one for each specified level of aggregations
> {(name, *), (*, *)}
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