```
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
public void testSplittingInWithFoldableValue() {
        FieldAttribute fa = getFieldAttribute("foo");
        In in = new In(EMPTY, ONE, List.of(TWO, THREE, fa, L(null)));
        Or expected = new Or(EMPTY, new In(EMPTY, ONE, List.of(TWO, THREE)), new In(EMPTY, ONE, List.of(fa, L(null))));
        assertThat(new LogicalPlanOptimizer.SplitInWithFoldableValue().rule(in), equalTo(expected));
    }
    public void testReplaceFilterWithExact() {
        var plan = plan("""
              from test
            | where job == "foo"
            """);
        var limit = as(plan, Limit.class);
        var filter = as(limit.child(), Filter.class);
        Equals equals = as(filter.condition(), Equals.class);
        FieldAttribute left = as(equals.left(), FieldAttribute.class);
        assertThat(left.name(), equalTo("job"));
    }
    public void testReplaceExpressionWithExact() {
        var plan = plan("""
              from test
            | eval x = job
            """);
        var eval = as(plan, Eval.class);
        var alias = as(eval.fields().get(0), Alias.class);
        var field = as(alias.child(), FieldAttribute.class);
        assertThat(field.name(), equalTo("job"));
    }
    public void testReplaceSortWithExact() {
        var plan = plan("""
              from test