morrySnow commented on code in PR #12274: URL: https://github.com/apache/doris/pull/12274#discussion_r962180863
########## fe/fe-core/src/main/java/org/apache/doris/nereids/rules/rewrite/logical/PruneAggChildColumns.java: ########## @@ -54,15 +59,65 @@ public class PruneAggChildColumns extends OneRewriteRuleFactory { @Override public Rule build() { return RuleType.COLUMN_PRUNE_AGGREGATION_CHILD.build(logicalAggregate().then(agg -> { + Slot slot = handleAggregateConstant(agg); + List<Slot> childOutput = agg.child().getOutput(); + if (slot != null) { + if (childOutput.size() == 1 && childOutput.get(0).equals(slot)) { + return agg; + } + return agg.withChildren(ImmutableList.of(new LogicalProject<>(ImmutableList.of(slot), agg.child()))); + } List<Expression> slots = Lists.newArrayList(); slots.addAll(agg.getExpressions()); Set<Slot> outputs = SlotExtractor.extractSlot(slots); - List<NamedExpression> prunedOutputs = agg.child().getOutput().stream().filter(outputs::contains) + List<NamedExpression> prunedOutputs = childOutput.stream().filter(outputs::contains) .collect(Collectors.toList()); if (prunedOutputs.size() == agg.child().getOutput().size()) { return agg; } return agg.withChildren(ImmutableList.of(new LogicalProject<>(prunedOutputs, agg.child()))); })); } + + /** + * For these aggregate function with constant param. Such as: + * count(*), count(1), sum(1)..etc. + * @return null, if there exists an aggregation function that its parameters contains non-constant expr. + * else return a slot with min data type. + */ + private Slot handleAggregateConstant(LogicalAggregate<GroupPlan> agg) { + List<NamedExpression> outputExpressions = agg.getOutputExpressions(); + for (NamedExpression namedExpression : outputExpressions) { + if (!(namedExpression instanceof Alias)) { + return null; + } + Expression childOfAlias = ((Alias) namedExpression).child(); + if (!(childOfAlias instanceof AggregateFunction)) { + return null; + } + if (childOfAlias instanceof Count) { + Count countFunc = (Count) childOfAlias; + if (!countFunc.isStar()) { + return null; + } + } else if (childOfAlias.children().stream().anyMatch(e -> !e.isConstant())) { Review Comment: as comment before, we should not relay on isConstant since we could create some function that generate random output. So it is not a constant but has no SlotReference neither. ########## fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/physical/PhysicalProject.java: ########## @@ -38,6 +38,7 @@ */ public class PhysicalProject<CHILD_TYPE extends Plan> extends PhysicalUnary<CHILD_TYPE> implements Project { + Review Comment: remove this blank line. -- 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: commits-unsubscr...@doris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org