
Filing this issue to track a question/comment that was raised by @ywangd  here https://github.com/elastic/elasticsearch/pull/98309#discussion_r1294115440

One question I do have is why we chose to [execute the LookupRequest with the enrich origin](https://github.com/elastic/elasticsearch/blob/2e4440ff1c0decf79f8a40688566411f7d518aa7/x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/enrich/EnrichLookupService.java#L141C2-L141C2). It means the following query works when the user has access to only the playlist index without access to either the songs enrich policy or its associated index.

```
FROM playlist | ENRICH songs ON song_id
```

It feels a bit weird to me that we have no control on who can use what enrich process. That said, we don't have a good story around enrich and ingest pipeline either, i.e. we have no control over who can use what pipeline where a pipeline can contain an enrich processor. There have been quite a few complaints from users and we have an https://github.com/elastic/elasticsearch/issues/57586 for it. I wonder whether we should not repeat the problem here with ES|QL. On the surface, it might be easier to tackle compared to ingest pipelines since ES|QL is read-only and has no "bulk" operations. What do you think?
x-pack/plugin/ql/src/main/java/org/elasticsearch/xpack/ql/expression/AttributeMap.java
}
            int i = 0;
            Object[] result = a;
            for (U u : this) {
                result[i++] = u;
            }
            
            if (a.length > size()) {
                a[size()] = null;
            }
            return a;
        }
        @Override
        public String toString() {
            return set.toString();
        }
    }
    @SuppressWarnings("rawtypes")
    private static final AttributeMap EMPTY = new AttributeMap<>();
    @SuppressWarnings("unchecked")
    public static final <E> AttributeMap<E> emptyAttributeMap() {
        return EMPTY;
    }
    private static final Object NOT_FOUND = new Object();
    private final Map<AttributeWrapper, E> delegate;
    private Set<Attribute> keySet = null;
    private Collection<E> values = null;
    private Set<Entry<Attribute, E>> entrySet = null;
    public AttributeMap() {
        delegate = new LinkedHashMap<>();