[jira] [Created] (OPTIQ-370) Support GROUPING SETS in SQL and algebra (AggregateRel)

[Julian Hyde (JIRA)]

Julian Hyde created OPTIQ-370:
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             Summary: Support GROUPING SETS in SQL and algebra (AggregateRel)
                 Key: OPTIQ-370
                 URL: https://issues.apache.org/jira/browse/OPTIQ-370
             Project: Optiq
          Issue Type: Bug
            Reporter: Julian Hyde
            Assignee: Julian Hyde


Support grouping sets in the relational algebra. This feature would add a new 
field, groupKeys, to aggregate rel that has a set of bit maps, each of which 
has a grouping key.

For example, if 'group by x, y, z' is represented by

{code}
AggregateRel(groupSet={0, 1, 2})
{code}

then 'group by grouping sets (x, y, z), (y, z), ()' would be represented by

{code}
AggregateRel(groupSet={0, 1, 2}, groupSets=[ {0, 1, 2}, {1, 2}, {} ])
{code}

A regular group by, or a group by with a singleton grouping set, would have 
groupSets = null.

If groupSets is present, the returned row type would include an indicator 
column for each grouping key.



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