
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/esql/src/main/java/org/elasticsearch/xpack/esql/optimizer/LogicalPlanOptimizer.java
@Override
        protected LogicalPlan rule(Limit limit) {
            if (limit.child() instanceof Limit childLimit) {
                var limitSource = limit.limit();
                var l1 = (int) limitSource.fold();
                var l2 = (int) childLimit.limit().fold();
                return new Limit(limit.source(), Literal.of(limitSource, Math.min(l1, l2)), childLimit.child());
            } else if (limit.child() instanceof UnaryPlan unary) {
                if (unary instanceof Eval || unary instanceof Project || unary instanceof RegexExtract || unary instanceof Enrich) {
                    return unary.replaceChild(limit.replaceChild(unary.child()));
                }
                
                
                
                else {
                    Limit descendantLimit = descendantLimit(unary);
                    if (descendantLimit != null) {
                        var l1 = (int) limit.limit().fold();
                        var l2 = (int) descendantLimit.limit().fold();