
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
}
    public E resolve(Object key, E defaultValue) {
        E value = defaultValue;
        E candidate = null;
        int allowedLookups = 1000;
        while ((candidate = get(key)) != null || containsKey(key)) {
            
            if (candidate == key) {
                return candidate;
            }
            if (--allowedLookups == 0) {
                throw new QlIllegalArgumentException("Potential cycle detected");
            }
            key = candidate;
            value = candidate;
        }
        return value;
    }
    @Override
    public E put(Attribute key, E value) {
        throw new UnsupportedOperationException();
    }
    @Override
    public E remove(Object key) {
        throw new UnsupportedOperationException();
    }
    @Override
    public void putAll(Map<? extends Attribute, ? extends E> m) {
        throw new UnsupportedOperationException();
    }