```
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/test/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizerTests.java
as(projections.get(1), ReferenceAttribute.class);
        assertThat(Expressions.name(aliased(projections.get(2), ReferenceAttribute.class)), is("min"));
        assertThat(Expressions.name(aliased(projections.get(3), ReferenceAttribute.class)), is("max"));
        var limit = as(project.child(), Limit.class);
        var agg = as(limit.child(), Aggregate.class);
        var aggs = agg.aggregates();
        assertThat(Expressions.names(aggs), contains("min", "max", "gender"));
        aggFieldName(aggs.get(0), Min.class, "salary");
        aggFieldName(aggs.get(1), Max.class, "salary");
        var source = as(agg.child(), EsRelation.class);
    }
    /**
     * Expects
     * EsqlProject[[a{r}#5, c{r}#8]]
     * \_Eval[[null[INTEGER] AS x]]
     *   \_EsRelation[test][_meta_field{f}#15, emp_no{f}#9, first_name{f}#10, g..]
     */
    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/100634")
    public void testEliminateDuplicateAggWithNull() {
        var plan = plan("""
              from test
            | eval x = null + 1
            | stats a = avg(x), c = count(x)
            """);
        fail("Awaits fix");
    }
    /**
     * Expects
     * Project[[max(x){r}#11, max(x){r}#11 AS max(y), max(x){r}#11 AS max(z)]]
     * \_Limit[500[INTEGER]]