Caideyipi commented on PR #17843:
URL: https://github.com/apache/iotdb/pull/17843#issuecomment-4628792737
I found two correctness issues in the alias resolution path:
1. `GROUP BY` input-column precedence currently treats outer-scope columns
as input columns. `resolvesToInputColumn()` calls
`scope.tryResolveField(...).isPresent()`, but that can resolve through the
query boundary into a correlated outer scope. As a result, a correlated
subquery such as:
```sql
SELECT x,
(SELECT COUNT(*) FROM table1 GROUP BY x)
FROM table_with_x
```
or an inner query with `SELECT expr AS x ... GROUP BY x` can have `GROUP BY
x` blocked from resolving to the inner SELECT alias just because the outer
query has a column named `x`. The stated rule is that `GROUP BY` prefers input
columns, which should mean the current query source scope, not outer query
columns. This should check the resolved field is local to the current source
scope, e.g. via `ResolvedField.isLocal()` / relation id, before suppressing
alias resolution.
2. `ORDER BY` aliases that point to window functions are re-analyzed as
window functions in the ORDER BY phase. For example:
```sql
SELECT row_number() OVER (ORDER BY s1) AS rn
FROM table1
ORDER BY rn
```
`ORDER BY rn` is rewritten to the `row_number() OVER (...)` expression, so
the function is collected both in `analysis.getWindowFunctions(node)` and
`analysis.getOrderByWindowFunctions(orderBy)`. `QueryPlanner` then plans SELECT
window functions first and ORDER BY window functions again after switching to
the ORDER BY scope, producing duplicate window planning instead of ordering by
the SELECT output alias. For ORDER BY alias references, the planner should
reuse the SELECT output symbol / field reference rather than treating the alias
target as a fresh ORDER BY window expression.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
