```
show functions | rename synopsis AS foo | stats bar = count(*) by foo | drop foo
```

```
{
    "error": {
        "root_cause": [
            {
                "type": "null_pointer_exception",
                "reason": "Cannot invoke \"org.elasticsearch.xpack.ql.expression.Attribute.id()\" because \"sourceAttribute\" is null"
            }
        ],
        "type": "null_pointer_exception",
        "reason": "Cannot invoke \"org.elasticsearch.xpack.ql.expression.Attribute.id()\" because \"sourceAttribute\" is null"
    },
    "status": 500
}
```

```
[2023-11-14T09:49:51,479][WARN ][r.suppressed             ] [runTask-0] path: /_query, params: {format=txt}, status: 500 java.lang.NullPointerException: Cannot invoke "org.elasticsearch.xpack.ql.expression.Attribute.id()" because "sourceAttribute" is null
        at org.elasticsearch.xpack.esql.planner.EsPhysicalOperationProviders.ordinalGroupingOperatorFactory(EsPhysicalOperationProviders.java:172)
        at org.elasticsearch.xpack.esql.planner.AbstractPhysicalOperationProviders.groupingPhysicalOperation(AbstractPhysicalOperationProviders.java:148)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planAggregation(LocalExecutionPlanner.java:234)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:182)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planAggregation(LocalExecutionPlanner.java:233)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:182)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planProject(LocalExecutionPlanner.java:571)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:196)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planLimit(LocalExecutionPlanner.java:610)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:200)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.planOutput(LocalExecutionPlanner.java:310)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:224)
        at org.elasticsearch.xpack.esql.planner.LocalExecutionPlanner.plan(LocalExecutionPlanner.java:168)
        at org.elasticsearch.xpack.esql.plugin.ComputeService.runCompute(ComputeService.java:260)
```
x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizer.java
if (agg instanceof Alias a && a.child() instanceof AggregateFunction aggFunc) {
                    List<Attribute> output = AbstractPhysicalOperationProviders.intermediateAttributes(List.of(agg), List.of());
                    for (Attribute o : output) {
                        DataType dataType = o.dataType();
                        
                        if (dataType != DataTypes.BOOLEAN) {
                            
                            var wrapper = BlockUtils.wrapperFor(blockFactory, LocalExecutionPlanner.toElementType(dataType), 1);
                            if (aggFunc instanceof Count count && (count.foldable() == false || count.fold() != null)) {
                                wrapper.accept(0L);
                            } else {
                                wrapper.accept(null);
                            }
                            blocks.add(wrapper.builder().build());
                        }
                    }
                } else {
                    throw new EsqlIllegalArgumentException("Did not expect a non-aliased aggregation {}", agg);
                }
            }
            return blocks;
        }
    }
    private static LogicalPlan skipPlan(UnaryPlan plan) {
        return new LocalRelation(plan.source(), plan.output(), LocalSupplier.EMPTY);
    }
    private static LogicalPlan skipPlan(UnaryPlan plan, LocalSupplier supplier) {
        return new LocalRelation(plan.source(), plan.output(), supplier);
    }
    protected static class PushDownAndCombineFilters extends OptimizerRules.OptimizerRule<Filter> {