This impacts the Grafana plugin.

From https://github.com/grafana/clickhouse-datasource/issues/198


    if an adhoc filter is specified for the field t1_distributed.f2
        the following query will be built by the plugin SELECT f1 from t1_distributed settings additional_table_filters = {'t1_distributed': 'f2 = xxx'}
        this query will actually not do its job of filtering
        i guess it is coming from the fact that additional_table_filters are applied by clickhouse when it reads the table....but distributed tables are not read.....
        if i replace in the built query, within the additional_table_filters settings, t1_distributed with t1_local (so a query like `SELECT f1 from t1_distributed settings additional_table_filters = {'t1_local': 'f2 = xxx'}), then it is working as expected
    i gave a try to add an adhoc filter on the "local" table (while my "main" query is still on the distributed table) (ie define an adhoc filter on the fied t1_local.f2)
        then the built query by the plugin does not include any additional_table_filters settings (i guess there is a check in order to add additional_table_filters only on the table used in the query)




if (log)
                LOG_TRACE(log, "Disabling force_optimize_skip_unused_shards for nested queries (force_optimize_skip_unused_shards_nesting exceeded)");
        }
        else
        {
            --new_settings.force_optimize_skip_unused_shards_nesting.value;
            new_settings.force_optimize_skip_unused_shards_nesting.changed = true;
            if (log)
                LOG_TRACE(log, "force_optimize_skip_unused_shards_nesting is now {}", new_settings.force_optimize_skip_unused_shards_nesting);
        }
    }
    if (settings.optimize_skip_unused_shards_nesting && settings.optimize_skip_unused_shards)
    {
        if (new_settings.optimize_skip_unused_shards_nesting == 1)
        {
            new_settings.optimize_skip_unused_shards = false;
            new_settings.optimize_skip_unused_shards.changed = false;
            if (log)
                LOG_TRACE(log, "Disabling optimize_skip_unused_shards for nested queries (optimize_skip_unused_shards_nesting exceeded)");
        }
        else
        {
            --new_settings.optimize_skip_unused_shards_nesting.value;
            new_settings.optimize_skip_unused_shards_nesting.changed = true;
            if (log)
                LOG_TRACE(log, "optimize_skip_unused_shards_nesting is now {}", new_settings.optimize_skip_unused_shards_nesting);
        }
    }
    if (settings.offset)
    {