private static DBAggregationQueryConfiguration loadQueryConfiguration() throws CannotLoadConfigurationException {
        return new DBAggregationConfigLoader().loadConfiguration();
    }
Checks and returns an instance of the RDBMS query configuration mapper.

@return an instance of {@link DBAggregationConfigurationMapper}.
@throws CannotLoadConfigurationException if the configuration cannot be loaded.
modules/siddhi-core/src/main/java/io/siddhi/core/aggregation/persistedaggregation/config/DBAggregationQueryUtil.java