private void cleanGroupByStates() {
        for (Map.Entry<String, PartitionIdStateHolder> partitionIdState : partitionIdStates.entrySet()) {
            for (Map.Entry<String, ElementStateHolder> queryState :
                    partitionIdState.getValue().queryStateHolderMap.entrySet()) {
                for (Map.Entry<String, StateHolder> elementState :
                        queryState.getValue().elementHolderMap.entrySet()) {
                    elementState.getValue().cleanGroupByStates();
                }
            }
        }
    }
Clear all the revisions of persistence store of Siddhi App
modules/siddhi-core/src/main/java/io/siddhi/core/util/snapshot/SnapshotService.java