### Description

This is to investigate what we could do to support the data streams in SQL. The backing indices can be queried already, but to address them similarly as they're queried over QDSL one would need to construct a pattern learned out of band and not through SQL metadata discovery mechanisms.
x-pack/plugin/ql/src/main/java/org/elasticsearch/xpack/ql/index/IndexResolver.java
listener.onFailure(ex);
                }
            }));
        } else {
            filterResults(javaRegex, indexInfos, listener);
        }
    }
    private void filterResults(String javaRegex, Set<IndexInfo> indexInfos, ActionListener<Set<IndexInfo>> listener) {
        
        Pattern pattern = javaRegex != null ? Pattern.compile(javaRegex) : null;
        Set<IndexInfo> result = new TreeSet<>(Comparator.comparing(IndexInfo::cluster).thenComparing(IndexInfo::name));
        for (IndexInfo indexInfo : indexInfos) {
            if (pattern == null || pattern.matcher(indexInfo.name()).matches()) {
                result.add(indexInfo);
            }
        }
        listener.onResponse(result);
    }
    private boolean clusterIsLocal(String clusterWildcard) {
        return clusterWildcard == null || simpleMatch(clusterWildcard, clusterName);
    }
    /**
     * Resolves a pattern to one (potentially compound meaning that spawns multiple indices) mapping.
     */
    public void resolveAsMergedMapping(
        String indexWildcard,
        IndicesOptions indicesOptions,
        Map<String, Object> runtimeMappings,
        ActionListener<IndexResolution> listener
    ) {