I'm currently working on CALCITE-6044. I have a problem that I thought would be
solved by mq.getAllPredicates(rel) but the output is from a perspective that
doesn't seem useful for my problem, which is, given this query:
select deptno, ename, sum(sal)from empwhere deptno=1010group by deptno, ename
and a call to areColumnsUnique(Aggregate rel, mq, bitSetOf(1), false), I'd like
it to return true. It currently returns true for columns {0, 1} on account that
those are the columns in the group by clause. However, it doesn't recognize
that since deptno is set to a constant, the remaining column (ename/1) is by
itself an effective key.
To solve this, I plan to collect a bitset of the constant columns (would be {0}
in this example), and remove those columns from the group-by columns. I thought
the way to collect those columns was to call mq.getAllPredicates(rel) and take
the columns from constantMap.keySet(), however, the RexInputRefs are relative
to the table scans (returning column 7 instead of 0), ignoring the effects on
column ordering of the projection and aggregation.
Is there an existing utility that can either transform these results or return
them from the perspective of the current RelNode?
Paul Jackson
