[CALCITE-7862] ARG_MIN and ARG_MAX should support ARRAY, MAP and ROW keys

[LantaoJin]

Jira Link

CALCITE-7862

Changes Proposed

ARG_MIN(value, key) and ARG_MAX(value, key), and their aliases MIN_BY and MAX_BY, pass validation when the key is an ARRAY, MAP or ROW, but the Enumerable convention cannot implement them. MIN, MAX and ORDER BY on the same values work.

select arg_min(x, v)
from (values (1, array[3, 1]), (2, array[1, 5]), (3, array[1, 4])) as t(x, v);

On main this fails with Unable to implement EnumerableAggregate(group=[{}], A=[ARG_MIN($0, $1)]), caused by NoSuchMethodException: SqlFunctions.ltNullable(java.util.List,java.util.List). With this change it returns 3.

Cause: ArgMinMaxImplementor compares a non-primitive key with SqlFunctions.ltNullable / gtNullable, which are only declared for T extends Comparable<T>. ARRAY, MAP and ROW values are List, Map and Object[] at run time, so code generation finds no method. CALCITE-4813 added overloads of lesser / greater for these types, which MIN / MAX use, but not of ltNullable / gtNullable.

Changes:

• SqlFunctions gets List, Map and Object[] overloads of ltNullable and gtNullable, which delegate to the existing lt / gt overloads for those types, so keys compare the same way as in MIN, MAX and ORDER BY.
• agg.iq covers ARG_MIN / ARG_MAX with ARRAY (including a NULL key, which is skipped), MAP and ROW keys, next to MIN / MAX on the same column. SqlOperatorTest.testArgMin covers an ARRAY key for ARG_MIN, ARG_MAX, MIN_BY and MAX_BY.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
84.8% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud