github-actions[bot] commented on code in PR #66898:
URL: https://github.com/apache/doris/pull/66898#discussion_r4118344043
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/algebra/CatalogRelation.java:
##########
@@ -43,4 +43,16 @@ default CatalogRelation withOperativeSlots(Collection<Slot>
operativeSlots) {
default List<Slot> getOperativeSlots() {
return ImmutableList.of();
}
+
+ /**
+ * Whether {@link #getOperativeSlots()} has been derived for this relation.
+ *
+ * <p>An empty operative slot list is a legitimate derivation result: a
relation that the query
+ * does not need any column of, e.g. the scan of {@code select count(*)
from wide_table}. The
+ * derivation state therefore must not be read from the slot list being
empty, since a relation
+ * whose slots have not been derived yet carries an empty list as well.
+ */
+ default boolean isOperativeSlotsDerived() {
Review Comment:
[P2] Carry the derived state into physical OLAP scans.
`LogicalOlapScanToPhysicalOlapScan` copies `operativeSlots`, but
`PhysicalOlapScan` inherits this default `false`. A reachable reduced plan is
`LogicalProject(66) -> PhysicalStorageLayerAggregate(COUNT,
relation=PhysicalOlapScan(wide, operative=[]))`: `AggregateStrategies` creates
the physical-only child group, `DeriveStatsJob` estimates it, and
`visitPhysicalStorageLayerAggregate` delegates to the embedded scan.
`getStatsNeededSlots` then expands a correct derived-empty result to every
output column, so `select 66` from a wide DUP table still triggers all
column-stat loads. This is independent of the logical-copy issue above;
propagate/preserve the boolean through logical-to-physical conversion and cover
the storage-aggregate path with a zero-load test.
##########
fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/logical/LogicalCatalogRelation.java:
##########
@@ -76,6 +76,8 @@ public abstract class LogicalCatalogRelation extends
LogicalRelation implements
*/
protected final String tableAlias;
+ private boolean operativeSlotsDerived;
Review Comment:
[P2] Preserve this state through logical scan copies. After the final
`OperativeColumnDerive`, `Memo.init` creates a `GroupExpression` for every
leaf; its constructor immediately calls `LogicalOlapScan.withGroupExpression`,
which constructs a fresh scan carrying `operativeSlots` while this field
returns to `false`. `Optimizer` then runs `DeriveStatsJob`, so
`getStatsNeededSlots` treats even `count(*)` as not derived and loads every
visible column. The same loss also occurs earlier in `SetPreAggStatus` before
`SkewJoin`. Thus the ordinary CBO path still performs the all-column loads this
PR is intended to remove. Make the derivation state immutable/carry it through
every semantics-preserving `withXxx` method and add memo-entry/rewrite-order
wide-table load-count coverage.
--
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]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
