[CALCITE-370] Support GROUPING SETS in SQL and algebra

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0-incubating
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 12/Aug/14 17:02
• Updated: 08/Feb/15 08:56
• Resolved: 14/Nov/14 22:02

Description

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

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

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

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

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.