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https://issues.apache.org/jira/browse/PHOENIX-136?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13955700#comment-13955700
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alex kamil edited comment on PHOENIX-136 at 3/31/14 9:15 PM:
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use case 1 (critical): cc @maryannxue
SELECT a.col1, b.col2, c.col3 FROM
(SELECT rk, col1 FROM table1 WHERE col1 LIKE 'foo%' AND col300 IS NULL) AS a
JOIN (SELECT rk, col2 FROM table2 WHERE col2 LIKE 'bar%') AS b ON a.rk=b.rk
JOIN (SELECT rk, col3 FROM table3 ) AS c ON a.rk=c.rk;
nice to have: TPC-H queries with nested SELECT: #2, 7, 9, 11,13,15-18,20-22
(http://www.tpc.org/tpch/spec/tpch2.16.0.pdf )
thanks!
was (Author: alexdl):
use case 1 (critical):
SELECT a.col1, b.col2, c.col3 FROM
(SELECT rk, col1 FROM table1 WHERE col1 LIKE 'foo%' AND col300 IS NULL) AS a
JOIN (SELECT rk, col2 FROM table2 WHERE col2 LIKE 'bar%') AS b ON a.rk=b.rk
JOIN (SELECT rk, col3 FROM table3 ) AS c ON a.rk=c.rk;
nice to have: TPC-H queries with nested SELECT: #2, 7, 9, 11,13,15-18,20-22
(http://www.tpc.org/tpch/spec/tpch2.16.0.pdf )
> Support derived tables
> ----------------------
>
> Key: PHOENIX-136
> URL: https://issues.apache.org/jira/browse/PHOENIX-136
> Project: Phoenix
> Issue Type: Task
> Reporter: James Taylor
> Assignee: James Taylor
> Labels: enhancement
>
> Add support for derived queries of the form:
> SELECT * FROM ( SELECT company, revenue FROM Company ORDER BY revenue) LIMIT
> 10
> Adding support for this requires a compile time change as well as a runtime
> execution change. The first version of the compile-time change could limit
> aggregation to only be allowed in the inner or the outer query, but not both.
> In this case, the inner and outer queries can be combined into a single query
> with the outer select becoming just a remapping of a subset of the projection
> from the inner select. The second version of the compile-time change could
> handle aggregation in the inner and outer select by performing client side
> (this is likely a less common scenario).
> For the runtime execution, change the UngroupedAggregateRegionObserver would
> be modified to look for a new "TopNLimit" attribute with an int value in the
> Scan. This would control the maximum number of values for the coprocessor to
> hold on to as the scan is performed. Then the
> GroupedAggregatingResultIterator would be modified to handle keeping the topN
> values received back from all the child iterators.
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