Stamatis Zampetakis created CALCITE-6461:
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Summary: Metadata provider for determining if columns originate
from aggregate functions
Key: CALCITE-6461
URL: https://issues.apache.org/jira/browse/CALCITE-6461
Project: Calcite
Issue Type: Improvement
Components: core
Reporter: Stamatis Zampetakis
Assignee: Stamatis Zampetakis
Add a new metadata provider for determining whether a set of columns originates
from aggregate functions.
In Apache Hive, we have a use-case where we need to determine if the columns in
the result of a query originate from aggregate functions. Along with other
things, it is used for deciding when to materialize common table expressions.
{code:sql}
SELECT job, SUM(sal) as total
FROM emp
GROUP BY job
{code}
For the query above, the new metadata provider should return:
* false when the input is column 0 (job)
* true when the input is column 1 (total)
* false when the input is columns {0,1}
The proposed metadata provider presents some similarities with {{ColumnOrigin}}
and {{ExpressionLineage}} but the latter cannot be easily extended to provide
this information.
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