```
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
GreaterThan conditionA = greaterThanOf(getFieldAttribute("a"), ONE);
        LessThan conditionB = lessThanOf(getFieldAttribute("b"), TWO);
        Filter fa = new Filter(EMPTY, relation, conditionA);
        List<FieldAttribute> projections = singletonList(getFieldAttribute("b"));
        EsqlProject keep = new EsqlProject(EMPTY, fa, projections);
        Filter fb = new Filter(EMPTY, keep, conditionB);
        Filter combinedFilter = new Filter(EMPTY, relation, new And(EMPTY, conditionA, conditionB));
        assertEquals(new EsqlProject(EMPTY, combinedFilter, projections), new LogicalPlanOptimizer.PushDownAndCombineFilters().apply(fb));
    }
    public void testPushDownLikeRlikeFilter() {
        EsRelation relation = relation();
        org.elasticsearch.xpack.ql.expression.predicate.regex.RLike conditionA = rlike(getFieldAttribute("a"), "foo");
        WildcardLike conditionB = wildcardLike(getFieldAttribute("b"), "bar");
        Filter fa = new Filter(EMPTY, relation, conditionA);
        List<FieldAttribute> projections = singletonList(getFieldAttribute("b"));
        EsqlProject keep = new EsqlProject(EMPTY, fa, projections);
        Filter fb = new Filter(EMPTY, keep, conditionB);
        Filter combinedFilter = new Filter(EMPTY, relation, new And(EMPTY, conditionA, conditionB));
        assertEquals(new EsqlProject(EMPTY, combinedFilter, projections), new LogicalPlanOptimizer.PushDownAndCombineFilters().apply(fb));
    }
    
    
    public void testSelectivelyPushDownFilterPastFunctionAgg() {
        EsRelation relation = relation();
        GreaterThan conditionA = greaterThanOf(getFieldAttribute("a"), ONE);
        LessThan conditionB = lessThanOf(getFieldAttribute("b"), TWO);
        GreaterThanOrEqual aggregateCondition = greaterThanOrEqualOf(new Count(EMPTY, ONE), THREE);
        Filter fa = new Filter(EMPTY, relation, conditionA);
        
        Aggregate aggregate = new Aggregate(EMPTY, fa, singletonList(getFieldAttribute("b")), emptyList());