### 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
IndicesOptions indicesOptions = includeFrozen ? FIELD_CAPS_FROZEN_INDICES_OPTIONS : FIELD_CAPS_INDICES_OPTIONS;
        return createFieldCapsRequest(index, indicesOptions, runtimeMappings);
    }
    /**
     * Resolves a pattern to multiple, separate indices. Doesn't perform validation.
     */
    public void resolveAsSeparateMappings(
        String indexWildcard,
        String javaRegex,
        boolean includeFrozen,
        Map<String, Object> runtimeMappings,
        ActionListener<List<EsIndex>> listener
    ) {
        FieldCapabilitiesRequest fieldRequest = createFieldCapsRequest(indexWildcard, includeFrozen, runtimeMappings);
        client.fieldCaps(fieldRequest, wrap(response -> {
            client.admin()
                .indices()
                .getAliases(
                    createGetAliasesRequest(response, includeFrozen),
                    wrap(
                        aliases -> { listener.onResponse(separateMappings(typeRegistry, javaRegex, response, aliases.getAliases())); },
                        ex -> {
                            if (ex instanceof IndexNotFoundException || ex instanceof ElasticsearchSecurityException) {
                                listener.onResponse(separateMappings(typeRegistry, javaRegex, response, null));
                            } else {
                                listener.onFailure(ex);
                            }
                        }
                    )
                );