```
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
});
                return p;
            });
            return plan;
        }
        private static LogicalPlan normalize(Aggregate aggregate, AttributeMap<Expression> aliases) {
            var aggs = aggregate.aggregates();
            List<NamedExpression> newAggs = new ArrayList<>(aggs.size());
            boolean changed = false;
            for (NamedExpression agg : aggs) {
                if (agg instanceof Alias as && as.child() instanceof AggregateFunction af) {
                    
                    if (af.field() instanceof NamedExpression ne) {
                        Attribute attr = ne.toAttribute();
                        var resolved = aliases.resolve(attr, attr);
                        if (resolved != attr) {
                            changed = true;
                            var newChildren = CollectionUtils.combine(Collections.singletonList(resolved), af.parameters());
                            
                            af = (AggregateFunction) af.replaceChildren(newChildren);
                            agg = as.replaceChild(af);
                        }
                    }
                    
                    if (af instanceof Count count) {
                        var field = af.field();
                        if (field.foldable()) {
                            var fold = field.fold();
                            if (fold != null && StringUtils.WILDCARD.equals(fold) == false) {
                                changed = true;