```
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
var eval = as(project.child(), Eval.class);
        var fields = eval.fields();
        assertThat(Expressions.names(fields), contains("c2", "cs", "cm", "cexp"));
        for (Alias field : fields) {
            assertThat(Expressions.name(field.child()), is("c1"));
        }
        var limit = as(eval.child(), Limit.class);
        var agg = as(limit.child(), Aggregate.class);
        var aggs = agg.aggregates();
        assertThat(Expressions.names(aggs), contains("c1"));
        aggFieldName(aggs.get(0), Count.class, "*");
        var source = as(agg.child(), EsRelation.class);
    }
    /**
     * Expects
     * Project[[c1{r}#7, cx{r}#10, cs{r}#12, cy{r}#15]]
     * \_Eval[[c1{r}#7 AS cx, c1{r}#7 AS cs, c1{r}#7 AS cy]]
     *   \_Limit[500[INTEGER]]
     *     \_Aggregate[[],[COUNT([2a][KEYWORD]) AS c1]]
     *       \_EsRelation[test][_meta_field{f}#22, emp_no{f}#16, first_name{f}#17, ..]
     */
    @AwaitsFix(bugUrl = "https://github.com/elastic/elasticsearch/issues/100634")
    public void testEliminateDuplicateAggsWithAliasedFields() {
        var plan = plan("""
              from test
            | eval x = 1
            | eval y = x
            | stats c1 = count(1), cx = count(x), cs = count(*), cy = count(y)
            """);
        var project = as(plan, Project.class);