Refactor cmHandle(ID) queries

- first execute cm-handle id search only
- get cm handles for ids only when needed using multiple-get-method
- use Collection interface where posisble (instead of Set)
- use java Function to combine multiple queries in a more genric way

Issue-ID: CPS-1494
Signed-off-by: seanbeirne <sean.beirne@est.tech>
Change-Id: Icfcb8ec94f75e261303aaee5c9034b920c01f3c4

7 files changed, 339 insertions, 442 deletions

diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyCmHandlerQueryService.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyCmHandleQueryService.java
index 7322ebc113..91e98e866b 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyCmHandlerQueryService.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyCmHandleQueryService.java
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022 Nordix Foundation
+ *  Copyright (C) 2022-2023 Nordix Foundation
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -20,18 +20,18 @@
 
 package org.onap.cps.ncmp.api;
 
-import java.util.Set;
+import java.util.Collection;
 import org.onap.cps.ncmp.api.models.CmHandleQueryServiceParameters;
 import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
 
-public interface NetworkCmProxyCmHandlerQueryService {
+public interface NetworkCmProxyCmHandleQueryService {
     /**
      * Query and return cm handles that match the given query parameters.
      *
      * @param cmHandleQueryServiceParameters the cm handle query parameters
      * @return collection of cm handles
      */
-    Set<NcmpServiceCmHandle> queryCmHandles(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
+    Collection<NcmpServiceCmHandle> queryCmHandles(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
 
     /**
      * Query and return cm handles that match the given query parameters.
@@ -39,7 +39,7 @@ public interface NetworkCmProxyCmHandlerQueryService {
      * @param cmHandleQueryServiceParameters the cm handle query parameters
      * @return collection of cm handle ids
      */
-    Set<String> queryCmHandleIds(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
+    Collection<String> queryCmHandleIds(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
 
     /**
      * Query and return cm handles that match the given query parameters.
@@ -47,5 +47,5 @@ public interface NetworkCmProxyCmHandlerQueryService {
      * @param cmHandleQueryServiceParameters the cm handle query parameters
      * @return collection of cm handle ids
      */
-    Set<String> queryCmHandleIdsForInventory(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
+    Collection<String> queryCmHandleIdsForInventory(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyDataService.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyDataService.java
index c9810e9a66..128eed3f2c 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyDataService.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/NetworkCmProxyDataService.java
@@ -1,7 +1,7 @@
 /*
  *  ============LICENSE_START=======================================================
  *  Copyright (C) 2021 highstreet technologies GmbH
- *  Modifications Copyright (C) 2021-2022 Nordix Foundation
+ *  Modifications Copyright (C) 2021-2023 Nordix Foundation
  *  Modifications Copyright (C) 2021 Pantheon.tech
  *  Modifications Copyright (C) 2022 Bell Canada
  *  ================================================================================
@@ -27,7 +27,6 @@ import static org.onap.cps.ncmp.api.impl.operations.DmiRequestBody.OperationEnum
 
 import java.util.Collection;
 import java.util.Map;
-import java.util.Set;
 import org.onap.cps.ncmp.api.inventory.CompositeState;
 import org.onap.cps.ncmp.api.models.CmHandleQueryApiParameters;
 import org.onap.cps.ncmp.api.models.CmHandleQueryServiceParameters;
@@ -159,7 +158,7 @@ public interface NetworkCmProxyDataService {
      * @param cmHandleQueryApiParameters the cm handle query parameters
      * @return collection of cm handles
      */
-    Set<NcmpServiceCmHandle> executeCmHandleSearch(CmHandleQueryApiParameters cmHandleQueryApiParameters);
+    Collection<NcmpServiceCmHandle> executeCmHandleSearch(CmHandleQueryApiParameters cmHandleQueryApiParameters);
 
     /**
      * Query and return cm handle ids that match the given query parameters.
@@ -167,7 +166,7 @@ public interface NetworkCmProxyDataService {
      * @param cmHandleQueryApiParameters the cm handle query parameters
      * @return collection of cm handle ids
      */
-    Set<String> executeCmHandleIdSearch(CmHandleQueryApiParameters cmHandleQueryApiParameters);
+    Collection<String> executeCmHandleIdSearch(CmHandleQueryApiParameters cmHandleQueryApiParameters);
 
     /**
      * Set the data sync enabled flag, along with the data sync state to true or false based on the cm handle id.
@@ -181,15 +180,16 @@ public interface NetworkCmProxyDataService {
      * Get all cm handle IDs by DMI plugin identifier.
      *
      * @param dmiPluginIdentifier DMI plugin identifier
-     * @return set of cm handle IDs
+     * @return collection of cm handle IDs
      */
-    Set<String> getAllCmHandleIdsByDmiPluginIdentifier(String dmiPluginIdentifier);
+    Collection<String> getAllCmHandleIdsByDmiPluginIdentifier(String dmiPluginIdentifier);
 
     /**
      * Get all cm handle IDs by various search criteria.
      *
      * @param cmHandleQueryServiceParameters cm handle query parameters
-     * @return set of cm handle IDs
+     * @return collection of cm handle IDs
      */
-    Set<String> executeCmHandleIdSearchForInventory(CmHandleQueryServiceParameters cmHandleQueryServiceParameters);
+    Collection<String> executeCmHandleIdSearchForInventory(CmHandleQueryServiceParameters
+                                                               cmHandleQueryServiceParameters);
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandleQueryServiceImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandleQueryServiceImpl.java
new file mode 100644
index 0000000000..54d89ba00e
--- /dev/null
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandleQueryServiceImpl.java
@@ -0,0 +1,268 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2022-2023 Nordix Foundation
+ *  Modifications Copyright (C) 2023 TechMahindra Ltd.
+ *  ================================================================================
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ *
+ *  SPDX-License-Identifier: Apache-2.0
+ *  ============LICENSE_END=========================================================
+ */
+
+package org.onap.cps.ncmp.api.impl;
+
+import static org.onap.cps.ncmp.api.impl.utils.CmHandleQueryConditions.HAS_ALL_MODULES;
+import static org.onap.cps.ncmp.api.impl.utils.CmHandleQueryConditions.HAS_ALL_PROPERTIES;
+import static org.onap.cps.ncmp.api.impl.utils.CmHandleQueryConditions.WITH_CPS_PATH;
+import static org.onap.cps.ncmp.api.impl.utils.RestQueryParametersValidator.validateCpsPathConditionProperties;
+import static org.onap.cps.ncmp.api.impl.utils.RestQueryParametersValidator.validateModuleNameConditionProperties;
+import static org.onap.cps.ncmp.api.impl.utils.YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle;
+import static org.onap.cps.spi.FetchDescendantsOption.DIRECT_CHILDREN_ONLY;
+import static org.onap.cps.spi.FetchDescendantsOption.OMIT_DESCENDANTS;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.onap.cps.cpspath.parser.PathParsingException;
+import org.onap.cps.ncmp.api.NetworkCmProxyCmHandleQueryService;
+import org.onap.cps.ncmp.api.impl.utils.InventoryQueryConditions;
+import org.onap.cps.ncmp.api.impl.utils.YangDataConverter;
+import org.onap.cps.ncmp.api.impl.yangmodels.YangModelCmHandle;
+import org.onap.cps.ncmp.api.inventory.CmHandleQueries;
+import org.onap.cps.ncmp.api.inventory.InventoryPersistence;
+import org.onap.cps.ncmp.api.inventory.enums.PropertyType;
+import org.onap.cps.ncmp.api.models.CmHandleQueryServiceParameters;
+import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
+import org.onap.cps.spi.exceptions.DataValidationException;
+import org.onap.cps.spi.model.ConditionProperties;
+import org.onap.cps.spi.model.DataNode;
+import org.springframework.stereotype.Service;
+
+@Service
+@Slf4j
+@RequiredArgsConstructor
+public class NetworkCmProxyCmHandleQueryServiceImpl implements NetworkCmProxyCmHandleQueryService {
+
+    private static final Collection<String> NO_QUERY_TO_EXECUTE = null;
+    private final CmHandleQueries cmHandleQueries;
+    private final InventoryPersistence inventoryPersistence;
+
+    @Override
+    public Collection<String> queryCmHandleIds(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+        return executeQueries(cmHandleQueryServiceParameters,
+            this::executeCpsPathQuery,
+            this::queryCmHandlesByPublicProperties,
+            this::executeModuleNameQuery);
+    }
+
+    @Override
+    public Collection<String> queryCmHandleIdsForInventory(
+        final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+        return executeQueries(cmHandleQueryServiceParameters,
+            this::queryCmHandlesByPublicProperties,
+            this::queryCmHandlesByPrivateProperties,
+            this::queryCmHandlesByDmiPlugin);
+    }
+
+    @Override
+    public Collection<NcmpServiceCmHandle> queryCmHandles(
+        final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+
+        if (cmHandleQueryServiceParameters.getCmHandleQueryParameters().isEmpty()) {
+            return getAllCmHandles();
+        }
+
+        final Collection<String> cmHandleIds = queryCmHandleIds(cmHandleQueryServiceParameters);
+
+        return getNcmpServiceCmHandles(cmHandleIds);
+    }
+
+    private Collection<String> queryCmHandlesByDmiPlugin(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+        final Map<String, String> dmiPropertyQueryPairs =
+                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
+                        InventoryQueryConditions.CM_HANDLE_WITH_DMI_PLUGIN.getName());
+        if (dmiPropertyQueryPairs.isEmpty()) {
+            return NO_QUERY_TO_EXECUTE;
+        }
+
+        final String dmiPluginIdentifierValue = dmiPropertyQueryPairs
+            .get(PropertyType.DMI_PLUGIN.getYangContainerName());
+
+        return cmHandleQueries.getCmHandleIdsByDmiPluginIdentifier(dmiPluginIdentifierValue);
+    }
+
+    private Collection<String> queryCmHandlesByPrivateProperties(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+
+        final Map<String, String> privatePropertyQueryPairs =
+                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
+                        InventoryQueryConditions.HAS_ALL_ADDITIONAL_PROPERTIES.getName());
+
+        return privatePropertyQueryPairs.isEmpty()
+                ? NO_QUERY_TO_EXECUTE
+                : cmHandleQueries.queryCmHandleAdditionalProperties(privatePropertyQueryPairs);
+    }
+
+    private Collection<String> queryCmHandlesByPublicProperties(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+
+        final Map<String, String> publicPropertyQueryPairs =
+                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
+                        HAS_ALL_PROPERTIES.getConditionName());
+
+        return publicPropertyQueryPairs.isEmpty()
+                ? NO_QUERY_TO_EXECUTE
+                : cmHandleQueries.queryCmHandlePublicProperties(publicPropertyQueryPairs);
+    }
+
+    private Collection<String> executeModuleNameQuery(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+        final Collection<String> moduleNamesForQuery =
+                getModuleNamesForQuery(cmHandleQueryServiceParameters.getCmHandleQueryParameters());
+        if (moduleNamesForQuery.isEmpty()) {
+            return NO_QUERY_TO_EXECUTE;
+        }
+        return inventoryPersistence.getCmHandleIdsWithGivenModules(moduleNamesForQuery);
+    }
+
+    private Collection<String> executeCpsPathQuery(
+            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
+        final Map<String, String> cpsPathCondition
+            = getCpsPathCondition(cmHandleQueryServiceParameters.getCmHandleQueryParameters());
+        if (!validateCpsPathConditionProperties(cpsPathCondition)) {
+            return Collections.emptySet();
+        }
+        final Collection<String> cpsPathQueryResult;
+        if (cpsPathCondition.isEmpty()) {
+            return NO_QUERY_TO_EXECUTE;
+        }
+        try {
+            cpsPathQueryResult = collectCmHandleIdsFromDataNodes(
+                cmHandleQueries.queryCmHandleDataNodesByCpsPath(cpsPathCondition.get("cpsPath"), OMIT_DESCENDANTS));
+        } catch (final PathParsingException pathParsingException) {
+            throw new DataValidationException(pathParsingException.getMessage(), pathParsingException.getDetails(),
+                    pathParsingException);
+        }
+        return cpsPathQueryResult;
+    }
+
+    private Collection<String> getModuleNamesForQuery(final List<ConditionProperties> conditionProperties) {
+        final List<String> result = new ArrayList<>();
+        getConditions(conditionProperties, HAS_ALL_MODULES.getConditionName()).forEach(
+                conditionProperty -> {
+                    validateModuleNameConditionProperties(conditionProperty);
+                    result.add(conditionProperty.get("moduleName"));
+                });
+        return result;
+    }
+
+    private Map<String, String> getCpsPathCondition(final List<ConditionProperties> conditionProperties) {
+        final Map<String, String> result = new HashMap<>();
+        getConditions(conditionProperties, WITH_CPS_PATH.getConditionName()).forEach(result::putAll);
+        return result;
+    }
+
+    private Map<String, String> getPropertyPairs(final List<ConditionProperties> conditionProperties,
+                                                       final String queryProperty) {
+        final Map<String, String> result = new HashMap<>();
+        getConditions(conditionProperties, queryProperty).forEach(result::putAll);
+        return result;
+    }
+
+    private List<Map<String, String>> getConditions(final List<ConditionProperties> conditionProperties,
+                                                    final String name) {
+        for (final ConditionProperties conditionProperty : conditionProperties) {
+            if (conditionProperty.getConditionName().equals(name)) {
+                return conditionProperty.getConditionParameters();
+            }
+        }
+        return Collections.emptyList();
+    }
+
+    private Collection<NcmpServiceCmHandle> getAllCmHandles() {
+        final DataNode dataNode = inventoryPersistence.getDataNode("/dmi-registry").iterator().next();
+        return dataNode.getChildDataNodes().stream().map(this::createNcmpServiceCmHandle).collect(Collectors.toSet());
+    }
+
+    private Collection<String> getAllCmHandleIds() {
+        final DataNode dataNode = inventoryPersistence.getDataNode("/dmi-registry", DIRECT_CHILDREN_ONLY)
+                .iterator().next();
+        return collectCmHandleIdsFromDataNodes(dataNode.getChildDataNodes());
+    }
+
+    private Collection<NcmpServiceCmHandle> getNcmpServiceCmHandles(final Collection<String> cmHandleIds) {
+        final Collection<YangModelCmHandle> yangModelcmHandles
+            = inventoryPersistence.getYangModelCmHandles(cmHandleIds);
+
+        final Collection<NcmpServiceCmHandle> ncmpServiceCmHandles = new ArrayList<>(yangModelcmHandles.size());
+
+        yangModelcmHandles.forEach(yangModelcmHandle ->
+            ncmpServiceCmHandles.add(YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle(yangModelcmHandle))
+        );
+        return ncmpServiceCmHandles;
+    }
+
+    private NcmpServiceCmHandle createNcmpServiceCmHandle(final DataNode dataNode) {
+        return convertYangModelCmHandleToNcmpServiceCmHandle(YangDataConverter
+                .convertCmHandleToYangModel(dataNode, dataNode.getLeaves().get("id").toString()));
+    }
+
+    private Collection<String> executeQueries(final CmHandleQueryServiceParameters cmHandleQueryServiceParameters,
+                                              final Function<CmHandleQueryServiceParameters, Collection<String>>...
+                                                  queryFunctions) {
+        if (cmHandleQueryServiceParameters.getCmHandleQueryParameters().isEmpty()) {
+            return getAllCmHandleIds();
+        }
+        Collection<String> combinedQueryResult = NO_QUERY_TO_EXECUTE;
+        for (final Function<CmHandleQueryServiceParameters, Collection<String>> queryFunction : queryFunctions) {
+            final Collection<String> queryResult = queryFunction.apply(cmHandleQueryServiceParameters);
+            if (noEntriesFoundCanStopQuerying(queryResult)) {
+                return Collections.emptySet();
+            }
+            combinedQueryResult = combineCmHandleQueryResults(combinedQueryResult, queryResult);
+        }
+        return combinedQueryResult;
+    }
+
+    private boolean noEntriesFoundCanStopQuerying(final Collection<String> queryResult) {
+        return queryResult != NO_QUERY_TO_EXECUTE && queryResult.isEmpty();
+    }
+
+    private Collection<String> combineCmHandleQueryResults(final Collection<String> firstQuery,
+                                                           final Collection<String> secondQuery) {
+        if (firstQuery == NO_QUERY_TO_EXECUTE && secondQuery == NO_QUERY_TO_EXECUTE) {
+            return NO_QUERY_TO_EXECUTE;
+        } else if (firstQuery == NO_QUERY_TO_EXECUTE) {
+            return secondQuery;
+        } else if (secondQuery == NO_QUERY_TO_EXECUTE) {
+            return firstQuery;
+        } else {
+            firstQuery.retainAll(secondQuery);
+            return firstQuery;
+        }
+    }
+
+    private Collection<String> collectCmHandleIdsFromDataNodes(final Collection<DataNode> dataNodes) {
+        return dataNodes.stream().map(dataNode -> (String) dataNode.getLeaves().get("id")).collect(Collectors.toSet());
+    }
+
+}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandlerQueryServiceImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandlerQueryServiceImpl.java
deleted file mode 100644
index f6f042dc12..0000000000
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyCmHandlerQueryServiceImpl.java
+++ /dev/null
@@ -1,317 +0,0 @@
-/*
- *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022-2023 Nordix Foundation
- *  Modifications Copyright (C) 2023 TechMahindra Ltd.
- *  ================================================================================
- *  Licensed under the Apache License, Version 2.0 (the "License");
- *  you may not use this file except in compliance with the License.
- *  You may obtain a copy of the License at
- *
- *        http://www.apache.org/licenses/LICENSE-2.0
- *
- *  Unless required by applicable law or agreed to in writing, software
- *  distributed under the License is distributed on an "AS IS" BASIS,
- *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- *  See the License for the specific language governing permissions and
- *  limitations under the License.
- *
- *  SPDX-License-Identifier: Apache-2.0
- *  ============LICENSE_END=========================================================
- */
-
-package org.onap.cps.ncmp.api.impl;
-
-import static org.onap.cps.ncmp.api.impl.utils.RestQueryParametersValidator.validateCpsPathConditionProperties;
-import static org.onap.cps.ncmp.api.impl.utils.RestQueryParametersValidator.validateModuleNameConditionProperties;
-import static org.onap.cps.ncmp.api.impl.utils.YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle;
-import static org.onap.cps.spi.FetchDescendantsOption.DIRECT_CHILDREN_ONLY;
-import static org.onap.cps.spi.FetchDescendantsOption.INCLUDE_ALL_DESCENDANTS;
-
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.function.Function;
-import java.util.stream.Collectors;
-import lombok.RequiredArgsConstructor;
-import lombok.extern.slf4j.Slf4j;
-import org.onap.cps.cpspath.parser.PathParsingException;
-import org.onap.cps.ncmp.api.NetworkCmProxyCmHandlerQueryService;
-import org.onap.cps.ncmp.api.impl.utils.CmHandleQueryConditions;
-import org.onap.cps.ncmp.api.impl.utils.InventoryQueryConditions;
-import org.onap.cps.ncmp.api.impl.utils.YangDataConverter;
-import org.onap.cps.ncmp.api.inventory.CmHandleQueries;
-import org.onap.cps.ncmp.api.inventory.InventoryPersistence;
-import org.onap.cps.ncmp.api.inventory.enums.PropertyType;
-import org.onap.cps.ncmp.api.models.CmHandleQueryServiceParameters;
-import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
-import org.onap.cps.spi.exceptions.DataValidationException;
-import org.onap.cps.spi.model.ConditionProperties;
-import org.onap.cps.spi.model.DataNode;
-import org.springframework.stereotype.Service;
-
-@Service
-@Slf4j
-@RequiredArgsConstructor
-public class NetworkCmProxyCmHandlerQueryServiceImpl implements NetworkCmProxyCmHandlerQueryService {
-
-    private static final Map<String, NcmpServiceCmHandle> NO_QUERY_TO_EXECUTE = null;
-    private final CmHandleQueries cmHandleQueries;
-    private final InventoryPersistence inventoryPersistence;
-
-    /**
-     * Query and return cm handles that match the given query parameters.
-     *
-     * @param cmHandleQueryServiceParameters the cm handle query parameters
-     * @return collection of cm handles
-     */
-    @Override
-    public Set<NcmpServiceCmHandle> queryCmHandles(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-
-        if (cmHandleQueryServiceParameters.getCmHandleQueryParameters().isEmpty()) {
-            return getAllCmHandles();
-        }
-
-        final Map<String, NcmpServiceCmHandle> combinedQueryResult = executeInventoryQueries(
-                cmHandleQueryServiceParameters);
-
-        return new HashSet<>(combineWithModuleNameQuery(cmHandleQueryServiceParameters, combinedQueryResult).values());
-    }
-
-    /**
-     * Query and return cm handles that match the given query parameters.
-     *
-     * @param cmHandleQueryServiceParameters the cm handle query parameters
-     * @return collection of cm handle ids
-     */
-    @Override
-    public Set<String> queryCmHandleIds(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-
-        if (cmHandleQueryServiceParameters.getCmHandleQueryParameters().isEmpty()) {
-            return getAllCmHandleIds();
-        }
-
-        final Map<String, NcmpServiceCmHandle> combinedQueryResult = executeInventoryQueries(
-                cmHandleQueryServiceParameters);
-
-        final Collection<String> moduleNamesForQuery =
-                getModuleNamesForQuery(cmHandleQueryServiceParameters.getCmHandleQueryParameters());
-        if (moduleNamesForQuery.isEmpty()) {
-            return combinedQueryResult.keySet();
-        }
-        final Set<String> moduleNameQueryResult =
-                new HashSet<>(inventoryPersistence.getCmHandleIdsWithGivenModules(moduleNamesForQuery));
-
-        if (combinedQueryResult == NO_QUERY_TO_EXECUTE) {
-            return moduleNameQueryResult;
-        }
-
-        moduleNameQueryResult.retainAll(combinedQueryResult.keySet());
-        return moduleNameQueryResult;
-    }
-
-    @Override
-    public Set<String> queryCmHandleIdsForInventory(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-
-        if (cmHandleQueryServiceParameters.getCmHandleQueryParameters().isEmpty()) {
-            return getAllCmHandleIds();
-        }
-
-        final Map<String, NcmpServiceCmHandle> publicPropertiesQueryResult = queryCmHandlesByPublicProperties(
-                cmHandleQueryServiceParameters);
-        if (publicPropertiesQueryResult != null && publicPropertiesQueryResult.isEmpty()) {
-            return Collections.emptySet();
-        }
-
-        final Map<String, NcmpServiceCmHandle> privatePropertiesQueryResult = queryCmHandlesByPrivateProperties(
-                cmHandleQueryServiceParameters);
-        if (privatePropertiesQueryResult != null && privatePropertiesQueryResult.isEmpty()) {
-            return Collections.emptySet();
-        }
-
-        final Map<String, NcmpServiceCmHandle> dmiPropertiesQueryResult = queryCmHandlesByDmiPlugin(
-                cmHandleQueryServiceParameters);
-        if (dmiPropertiesQueryResult != null && dmiPropertiesQueryResult.isEmpty()) {
-            return Collections.emptySet();
-        }
-
-        final Map<String, NcmpServiceCmHandle> combinedResult =
-              combineQueryResults(publicPropertiesQueryResult, privatePropertiesQueryResult, dmiPropertiesQueryResult);
-
-        return combinedResult.keySet();
-    }
-
-    private Map<String, NcmpServiceCmHandle> queryCmHandlesByDmiPlugin(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-        final Map<String, String> dmiPropertyQueryPairs =
-                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
-                        InventoryQueryConditions.CM_HANDLE_WITH_DMI_PLUGIN.getName());
-        if (dmiPropertyQueryPairs.isEmpty()) {
-            return NO_QUERY_TO_EXECUTE;
-        }
-
-        final String dmiPluginIdentifierValue = dmiPropertyQueryPairs.get(
-                PropertyType.DMI_PLUGIN.getYangContainerName());
-
-        final Set<NcmpServiceCmHandle> cmHandlesByDmiPluginIdentifier = cmHandleQueries
-                .getCmHandlesByDmiPluginIdentifier(dmiPluginIdentifierValue);
-
-        return cmHandlesByDmiPluginIdentifier.stream()
-                .collect(Collectors.toMap(NcmpServiceCmHandle::getCmHandleId, cmH -> cmH));
-    }
-
-    private Map<String, NcmpServiceCmHandle> queryCmHandlesByPrivateProperties(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-
-        final Map<String, String> privatePropertyQueryPairs =
-                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
-                        InventoryQueryConditions.HAS_ALL_ADDITIONAL_PROPERTIES.getName());
-
-        return privatePropertyQueryPairs.isEmpty()
-                ? NO_QUERY_TO_EXECUTE
-                : cmHandleQueries.queryCmHandleAdditionalProperties(privatePropertyQueryPairs);
-    }
-
-    private Map<String, NcmpServiceCmHandle> queryCmHandlesByPublicProperties(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-
-        final Map<String, String> publicPropertyQueryPairs =
-                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
-                        CmHandleQueryConditions.HAS_ALL_PROPERTIES.getConditionName());
-
-        return publicPropertyQueryPairs.isEmpty()
-                ? NO_QUERY_TO_EXECUTE
-                : cmHandleQueries.queryCmHandlePublicProperties(publicPropertyQueryPairs);
-    }
-
-    private Map<String, NcmpServiceCmHandle> combineQueryResults(
-            final Map<String, NcmpServiceCmHandle> publicPropertiesQueryResult,
-            final Map<String, NcmpServiceCmHandle> privatePropertiesQueryResult,
-            final Map<String, NcmpServiceCmHandle> dmiPropertiesQueryResult) {
-
-        final Map<String, NcmpServiceCmHandle> propertiesCombinedResult = cmHandleQueries
-                .combineCmHandleQueries(publicPropertiesQueryResult, privatePropertiesQueryResult);
-        return cmHandleQueries
-                .combineCmHandleQueries(propertiesCombinedResult, dmiPropertiesQueryResult);
-    }
-
-    private Map<String, NcmpServiceCmHandle> combineWithModuleNameQuery(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters,
-            final Map<String, NcmpServiceCmHandle> previousQueryResult) {
-        final Collection<String> moduleNamesForQuery =
-                getModuleNamesForQuery(cmHandleQueryServiceParameters.getCmHandleQueryParameters());
-        if (moduleNamesForQuery.isEmpty()) {
-            return previousQueryResult;
-        }
-        final Collection<String> cmHandleIdsByModuleName =
-                inventoryPersistence.getCmHandleIdsWithGivenModules(moduleNamesForQuery);
-        if (cmHandleIdsByModuleName.isEmpty()) {
-            return Collections.emptyMap();
-        }
-        final Map<String, NcmpServiceCmHandle> queryResult = new HashMap<>(cmHandleIdsByModuleName.size());
-        if (previousQueryResult == NO_QUERY_TO_EXECUTE) {
-            cmHandleIdsByModuleName.forEach(cmHandleId ->
-                    queryResult.put(cmHandleId, createNcmpServiceCmHandle(inventoryPersistence
-                            .getDataNode("/dmi-registry/cm-handles[@id='" + cmHandleId + "']").iterator().next()))
-            );
-            return queryResult;
-        }
-        previousQueryResult.keySet().retainAll(cmHandleIdsByModuleName);
-        queryResult.putAll(previousQueryResult);
-        return queryResult;
-    }
-
-    private Map<String, NcmpServiceCmHandle> executeInventoryQueries(
-            final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
-        final Map<String, String> cpsPath = getCpsPath(cmHandleQueryServiceParameters.getCmHandleQueryParameters());
-        if (!validateCpsPathConditionProperties(cpsPath)) {
-            return Collections.emptyMap();
-        }
-        final Map<String, NcmpServiceCmHandle> cpsPathQueryResult;
-        if (cpsPath.isEmpty()) {
-            cpsPathQueryResult = NO_QUERY_TO_EXECUTE;
-        } else {
-            try {
-                cpsPathQueryResult = cmHandleQueries.queryCmHandleDataNodesByCpsPath(
-                                cpsPath.get("cpsPath"), INCLUDE_ALL_DESCENDANTS)
-                        .stream().map(this::createNcmpServiceCmHandle)
-                        .collect(Collectors.toMap(NcmpServiceCmHandle::getCmHandleId,
-                                Function.identity()));
-            } catch (final PathParsingException pathParsingException) {
-                throw new DataValidationException(pathParsingException.getMessage(), pathParsingException.getDetails(),
-                        pathParsingException);
-            }
-            if (cpsPathQueryResult.isEmpty()) {
-                return Collections.emptyMap();
-            }
-        }
-
-        final Map<String, String> publicPropertyQueryPairs =
-                getPropertyPairs(cmHandleQueryServiceParameters.getCmHandleQueryParameters(),
-                        CmHandleQueryConditions.HAS_ALL_PROPERTIES.getConditionName());
-        final Map<String, NcmpServiceCmHandle> propertiesQueryResult = publicPropertyQueryPairs.isEmpty()
-                ? NO_QUERY_TO_EXECUTE : cmHandleQueries.queryCmHandlePublicProperties(publicPropertyQueryPairs);
-
-        return cmHandleQueries.combineCmHandleQueries(cpsPathQueryResult, propertiesQueryResult);
-    }
-
-    private Collection<String> getModuleNamesForQuery(final List<ConditionProperties> conditionProperties) {
-        final List<String> result = new ArrayList<>();
-        getConditions(conditionProperties, CmHandleQueryConditions.HAS_ALL_MODULES.getConditionName())
-            .parallelStream().forEach(
-                conditionProperty -> {
-                    validateModuleNameConditionProperties(conditionProperty);
-                    result.add(conditionProperty.get("moduleName"));
-                }
-            );
-        return result;
-    }
-
-    private Map<String, String> getCpsPath(final List<ConditionProperties> conditionProperties) {
-        final Map<String, String> result = new HashMap<>();
-        getConditions(conditionProperties, CmHandleQueryConditions.WITH_CPS_PATH.getConditionName()).forEach(
-                result::putAll);
-        return result;
-    }
-
-    private Map<String, String> getPropertyPairs(final List<ConditionProperties> conditionProperties,
-                                                       final String queryProperty) {
-        final Map<String, String> result = new HashMap<>();
-        getConditions(conditionProperties, queryProperty).forEach(result::putAll);
-        return result;
-    }
-
-    private List<Map<String, String>> getConditions(final List<ConditionProperties> conditionProperties,
-                                                    final String name) {
-        for (final ConditionProperties conditionProperty : conditionProperties) {
-            if (conditionProperty.getConditionName().equals(name)) {
-                return conditionProperty.getConditionParameters();
-            }
-        }
-        return Collections.emptyList();
-    }
-
-    private Set<NcmpServiceCmHandle> getAllCmHandles() {
-        final DataNode dataNode = inventoryPersistence.getDataNode("/dmi-registry").iterator().next();
-        return dataNode.getChildDataNodes().stream().map(this::createNcmpServiceCmHandle).collect(Collectors.toSet());
-    }
-
-    private Set<String> getAllCmHandleIds() {
-        final DataNode dataNodes = inventoryPersistence.getDataNode("/dmi-registry", DIRECT_CHILDREN_ONLY)
-                .iterator().next();
-        return dataNodes.getChildDataNodes().stream().map(dataNode -> dataNode.getLeaves().get("id").toString())
-                .collect(Collectors.toSet());
-    }
-
-    private NcmpServiceCmHandle createNcmpServiceCmHandle(final DataNode dataNode) {
-        return convertYangModelCmHandleToNcmpServiceCmHandle(YangDataConverter
-                .convertCmHandleToYangModel(dataNode, dataNode.getLeaves().get("id").toString()));
-    }
-}
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyDataServiceImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyDataServiceImpl.java
index d26a59b054..d3a4f530f1 100755
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyDataServiceImpl.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/impl/NetworkCmProxyDataServiceImpl.java
@@ -42,7 +42,7 @@ import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.onap.cps.api.CpsDataService;
-import org.onap.cps.ncmp.api.NetworkCmProxyCmHandlerQueryService;
+import org.onap.cps.ncmp.api.NetworkCmProxyCmHandleQueryService;
 import org.onap.cps.ncmp.api.NetworkCmProxyDataService;
 import org.onap.cps.ncmp.api.impl.event.lcm.LcmEventsCmHandleStateHandler;
 import org.onap.cps.ncmp.api.impl.operations.DmiDataOperations;
@@ -86,7 +86,7 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
     private final NetworkCmProxyDataServicePropertyHandler networkCmProxyDataServicePropertyHandler;
     private final InventoryPersistence inventoryPersistence;
     private final CmHandleQueries cmHandleQueries;
-    private final NetworkCmProxyCmHandlerQueryService networkCmProxyCmHandlerQueryService;
+    private final NetworkCmProxyCmHandleQueryService networkCmProxyCmHandleQueryService;
     private final LcmEventsCmHandleStateHandler lcmEventsCmHandleStateHandler;
     private final CpsDataService cpsDataService;
     private final IMap<String, Object> moduleSyncStartedOnCmHandles;
@@ -177,11 +177,12 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
      * @return cm handles with details
      */
     @Override
-    public Set<NcmpServiceCmHandle> executeCmHandleSearch(final CmHandleQueryApiParameters cmHandleQueryApiParameters) {
+    public Collection<NcmpServiceCmHandle> executeCmHandleSearch(
+            final CmHandleQueryApiParameters cmHandleQueryApiParameters) {
         final CmHandleQueryServiceParameters cmHandleQueryServiceParameters = jsonObjectMapper.convertToValueType(
                 cmHandleQueryApiParameters, CmHandleQueryServiceParameters.class);
         validateCmHandleQueryParameters(cmHandleQueryServiceParameters, CmHandleQueryConditions.ALL_CONDITION_NAMES);
-        return networkCmProxyCmHandlerQueryService.queryCmHandles(cmHandleQueryServiceParameters);
+        return networkCmProxyCmHandleQueryService.queryCmHandles(cmHandleQueryServiceParameters);
     }
 
     /**
@@ -191,11 +192,11 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
      * @return cm handle ids
      */
     @Override
-    public Set<String> executeCmHandleIdSearch(final CmHandleQueryApiParameters cmHandleQueryApiParameters) {
+    public Collection<String> executeCmHandleIdSearch(final CmHandleQueryApiParameters cmHandleQueryApiParameters) {
         final CmHandleQueryServiceParameters cmHandleQueryServiceParameters = jsonObjectMapper.convertToValueType(
                 cmHandleQueryApiParameters, CmHandleQueryServiceParameters.class);
         validateCmHandleQueryParameters(cmHandleQueryServiceParameters, CmHandleQueryConditions.ALL_CONDITION_NAMES);
-        return networkCmProxyCmHandlerQueryService.queryCmHandleIds(cmHandleQueryServiceParameters);
+        return networkCmProxyCmHandleQueryService.queryCmHandleIds(cmHandleQueryServiceParameters);
     }
 
     /**
@@ -234,12 +235,8 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
      * @return set of cm handle IDs
      */
     @Override
-    public Set<String> getAllCmHandleIdsByDmiPluginIdentifier(final String dmiPluginIdentifier) {
-        final Set<NcmpServiceCmHandle> ncmpServiceCmHandles =
-                cmHandleQueries.getCmHandlesByDmiPluginIdentifier(dmiPluginIdentifier);
-        final Set<String> cmHandleIds = new HashSet<>(ncmpServiceCmHandles.size());
-        ncmpServiceCmHandles.forEach(cmHandle -> cmHandleIds.add(cmHandle.getCmHandleId()));
-        return cmHandleIds;
+    public Collection<String> getAllCmHandleIdsByDmiPluginIdentifier(final String dmiPluginIdentifier) {
+        return cmHandleQueries.getCmHandleIdsByDmiPluginIdentifier(dmiPluginIdentifier);
     }
 
     /**
@@ -249,10 +246,10 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
      * @return set of cm handle IDs
      */
     @Override
-    public Set<String> executeCmHandleIdSearchForInventory(
+    public Collection<String> executeCmHandleIdSearchForInventory(
             final CmHandleQueryServiceParameters cmHandleQueryServiceParameters) {
         validateCmHandleQueryParameters(cmHandleQueryServiceParameters, InventoryQueryConditions.ALL_CONDITION_NAMES);
-        return networkCmProxyCmHandlerQueryService.queryCmHandleIdsForInventory(cmHandleQueryServiceParameters);
+        return networkCmProxyCmHandleQueryService.queryCmHandleIdsForInventory(cmHandleQueryServiceParameters);
     }
 
     /**
@@ -426,4 +423,5 @@ public class NetworkCmProxyDataServiceImpl implements NetworkCmProxyDataService
             return CmHandleRegistrationResponse.createFailureResponses(cmHandleIds, exception);
         }
     }
+
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueries.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueries.java
index bae0262b07..ff78f00229 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueries.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueries.java
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022 Nordix Foundation
+ *  Copyright (C) 2022-2023 Nordix Foundation
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
  *  you may not use this file except in compliance with the License.
@@ -20,10 +20,9 @@
 
 package org.onap.cps.ncmp.api.inventory;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
-import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
 import org.onap.cps.spi.FetchDescendantsOption;
 import org.onap.cps.spi.model.DataNode;
 
@@ -33,10 +32,9 @@ public interface CmHandleQueries {
      * Query CmHandles based on additional (private) properties.
      *
      * @param additionalPropertyQueryPairs private properties for query
-     * @return CmHandles which have these private properties
+     * @return Ids of CmHandles which have these private properties
      */
-    Map<String, NcmpServiceCmHandle> queryCmHandleAdditionalProperties(
-            Map<String, String> additionalPropertyQueryPairs);
+    Collection<String> queryCmHandleAdditionalProperties(Map<String, String> additionalPropertyQueryPairs);
 
     /**
      * Query CmHandles based on public properties.
@@ -44,18 +42,7 @@ public interface CmHandleQueries {
      * @param publicPropertyQueryPairs public properties for query
      * @return CmHandles which have these public properties
      */
-    Map<String, NcmpServiceCmHandle> queryCmHandlePublicProperties(
-            Map<String, String> publicPropertyQueryPairs);
-
-    /**
-     * Combine Maps of CmHandles.
-     *
-     * @param firstQuery  first CmHandles Map
-     * @param secondQuery second CmHandles Map
-     * @return combined Map of CmHandles
-     */
-    Map<String, NcmpServiceCmHandle> combineCmHandleQueries(Map<String, NcmpServiceCmHandle> firstQuery,
-            Map<String, NcmpServiceCmHandle> secondQuery);
+    Collection<String> queryCmHandlePublicProperties(Map<String, String> publicPropertyQueryPairs);
 
     /**
      * Method which returns cm handles by the cm handles state.
@@ -91,10 +78,10 @@ public interface CmHandleQueries {
     List<DataNode> queryCmHandlesByOperationalSyncState(DataStoreSyncState dataStoreSyncState);
 
     /**
-     * Get all cm handles by DMI plugin identifier.
+     * Get all cm handles ids by DMI plugin identifier.
      *
      * @param dmiPluginIdentifier DMI plugin identifier
-     * @return set of cm handles
+     * @return collection of cm handles
      */
-    Set<NcmpServiceCmHandle> getCmHandlesByDmiPluginIdentifier(String dmiPluginIdentifier);
+    Collection<String> getCmHandleIdsByDmiPluginIdentifier(String dmiPluginIdentifier);
 }
diff --git a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueriesImpl.java b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueriesImpl.java
index 0f86cb7be6..f61d6c348a 100644
--- a/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueriesImpl.java
+++ b/cps-ncmp-service/src/main/java/org/onap/cps/ncmp/api/inventory/CmHandleQueriesImpl.java
@@ -1,6 +1,6 @@
 /*
  *  ============LICENSE_START=======================================================
- *  Copyright (C) 2022 Nordix Foundation
+ *  Copyright (C) 2022-2023 Nordix Foundation
  *  Modifications Copyright (C) 2023 TechMahindra Ltd.
  *  ================================================================================
  *  Licensed under the Apache License, Version 2.0 (the "License");
@@ -21,22 +21,17 @@
 
 package org.onap.cps.ncmp.api.inventory;
 
-import static org.onap.cps.ncmp.api.impl.utils.YangDataConverter.convertYangModelCmHandleToNcmpServiceCmHandle;
 import static org.onap.cps.spi.FetchDescendantsOption.INCLUDE_ALL_DESCENDANTS;
 import static org.onap.cps.spi.FetchDescendantsOption.OMIT_DESCENDANTS;
 
 import java.util.Collection;
 import java.util.Collections;
-import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.stream.Collectors;
 import lombok.RequiredArgsConstructor;
-import org.onap.cps.ncmp.api.impl.utils.YangDataConverter;
 import org.onap.cps.ncmp.api.inventory.enums.PropertyType;
-import org.onap.cps.ncmp.api.models.NcmpServiceCmHandle;
 import org.onap.cps.spi.CpsDataPersistenceService;
 import org.onap.cps.spi.FetchDescendantsOption;
 import org.onap.cps.spi.model.DataNode;
@@ -51,63 +46,18 @@ public class CmHandleQueriesImpl implements CmHandleQueries {
     private static final String DESCENDANT_PATH = "//";
 
     private final CpsDataPersistenceService cpsDataPersistenceService;
-    private static final Map<String, NcmpServiceCmHandle> NO_QUERY_TO_EXECUTE = null;
     private static final String ANCESTOR_CM_HANDLES = "/ancestor::cm-handles";
 
     @Override
-    public Map<String, NcmpServiceCmHandle> queryCmHandleAdditionalProperties(
-            final Map<String, String> privatePropertyQueryPairs) {
+    public Collection<String> queryCmHandleAdditionalProperties(final Map<String, String> privatePropertyQueryPairs) {
         return queryCmHandleAnyProperties(privatePropertyQueryPairs, PropertyType.ADDITIONAL);
     }
 
     @Override
-    public Map<String, NcmpServiceCmHandle> queryCmHandlePublicProperties(
-            final Map<String, String> publicPropertyQueryPairs) {
+    public Collection<String> queryCmHandlePublicProperties(final Map<String, String> publicPropertyQueryPairs) {
         return queryCmHandleAnyProperties(publicPropertyQueryPairs, PropertyType.PUBLIC);
     }
 
-    private  Map<String, NcmpServiceCmHandle> queryCmHandleAnyProperties(
-            final Map<String, String> propertyQueryPairs,
-            final PropertyType propertyType) {
-        if (propertyQueryPairs.isEmpty()) {
-            return Collections.emptyMap();
-        }
-        Map<String, NcmpServiceCmHandle> cmHandleIdToNcmpServiceCmHandles = null;
-        for (final Map.Entry<String, String> publicPropertyQueryPair : propertyQueryPairs.entrySet()) {
-            final String cpsPath = DESCENDANT_PATH + propertyType.getYangContainerName() + "[@name=\""
-                    + publicPropertyQueryPair.getKey()
-                    + "\" and @value=\"" + publicPropertyQueryPair.getValue() + "\"]";
-
-            final Collection<DataNode> dataNodes = queryCmHandleDataNodesByCpsPath(cpsPath, INCLUDE_ALL_DESCENDANTS);
-            if (cmHandleIdToNcmpServiceCmHandles == null) {
-                cmHandleIdToNcmpServiceCmHandles = collectDataNodesToNcmpServiceCmHandles(dataNodes);
-            } else {
-                final Collection<String> cmHandleIdsToRetain = dataNodes.parallelStream()
-                        .map(dataNode -> dataNode.getLeaves().get("id").toString()).collect(Collectors.toSet());
-                cmHandleIdToNcmpServiceCmHandles.keySet().retainAll(cmHandleIdsToRetain);
-            }
-            if (cmHandleIdToNcmpServiceCmHandles.isEmpty()) {
-                break;
-            }
-        }
-        return cmHandleIdToNcmpServiceCmHandles;
-    }
-
-    @Override
-    public Map<String, NcmpServiceCmHandle> combineCmHandleQueries(final Map<String, NcmpServiceCmHandle> firstQuery,
-            final Map<String, NcmpServiceCmHandle> secondQuery) {
-        if (firstQuery == NO_QUERY_TO_EXECUTE && secondQuery == NO_QUERY_TO_EXECUTE) {
-            return NO_QUERY_TO_EXECUTE;
-        } else if (firstQuery == NO_QUERY_TO_EXECUTE) {
-            return secondQuery;
-        } else if (secondQuery == NO_QUERY_TO_EXECUTE) {
-            return firstQuery;
-        } else {
-            firstQuery.keySet().retainAll(secondQuery.keySet());
-            return firstQuery;
-        }
-    }
-
     @Override
     public List<DataNode> queryCmHandlesByState(final CmHandleState cmHandleState) {
         return queryCmHandleDataNodesByCpsPath("//state[@cm-handle-state=\"" + cmHandleState + "\"]",
@@ -134,36 +84,47 @@ public class CmHandleQueriesImpl implements CmHandleQueries {
                 + dataStoreSyncState + "\"]", FetchDescendantsOption.OMIT_DESCENDANTS);
     }
 
-    private Map<String, NcmpServiceCmHandle> collectDataNodesToNcmpServiceCmHandles(
-            final Collection<DataNode> dataNodes) {
-        final Map<String, NcmpServiceCmHandle> cmHandleIdToNcmpServiceCmHandle = new HashMap<>();
-        dataNodes.forEach(dataNode -> {
-            final NcmpServiceCmHandle ncmpServiceCmHandle = createNcmpServiceCmHandle(dataNode);
-            cmHandleIdToNcmpServiceCmHandle.put(ncmpServiceCmHandle.getCmHandleId(), ncmpServiceCmHandle);
-        });
-        return cmHandleIdToNcmpServiceCmHandle;
-    }
-
-    private NcmpServiceCmHandle createNcmpServiceCmHandle(final DataNode dataNode) {
-        return convertYangModelCmHandleToNcmpServiceCmHandle(YangDataConverter
-                .convertCmHandleToYangModel(dataNode, dataNode.getLeaves().get("id").toString()));
-    }
-
     @Override
-    public Set<NcmpServiceCmHandle> getCmHandlesByDmiPluginIdentifier(final String dmiPluginIdentifier) {
-        final Map<String, DataNode> cmHandleAsDataNodePerCmHandleId = new HashMap<>();
+    public Collection<String> getCmHandleIdsByDmiPluginIdentifier(final String dmiPluginIdentifier) {
+        final Collection<String> cmHandleIds = new HashSet<>();
         for (final ModelledDmiServiceLeaves modelledDmiServiceLeaf : ModelledDmiServiceLeaves.values()) {
             for (final DataNode cmHandleAsDataNode: getCmHandlesByDmiPluginIdentifierAndDmiProperty(
                     dmiPluginIdentifier,
                     modelledDmiServiceLeaf.getLeafName())) {
-                cmHandleAsDataNodePerCmHandleId.put(
-                        cmHandleAsDataNode.getLeaves().get("id").toString(), cmHandleAsDataNode);
+                cmHandleIds.add(cmHandleAsDataNode.getLeaves().get("id").toString());
+            }
+        }
+        return cmHandleIds;
+    }
+
+    private Collection<String> collectCmHandleIdsFromDataNodes(final Collection<DataNode> dataNodes) {
+        return dataNodes.stream().map(dataNode -> (String) dataNode.getLeaves().get("id")).collect(Collectors.toSet());
+    }
+
+    private Collection<String> queryCmHandleAnyProperties(
+        final Map<String, String> propertyQueryPairs,
+        final PropertyType propertyType) {
+        if (propertyQueryPairs.isEmpty()) {
+            return Collections.emptySet();
+        }
+        Collection<String> cmHandleIds = null;
+        for (final Map.Entry<String, String> publicPropertyQueryPair : propertyQueryPairs.entrySet()) {
+            final String cpsPath = DESCENDANT_PATH + propertyType.getYangContainerName() + "[@name=\""
+                + publicPropertyQueryPair.getKey()
+                + "\" and @value=\"" + publicPropertyQueryPair.getValue() + "\"]";
+
+            final Collection<DataNode> dataNodes = queryCmHandleDataNodesByCpsPath(cpsPath, OMIT_DESCENDANTS);
+            if (cmHandleIds == null) {
+                cmHandleIds = collectCmHandleIdsFromDataNodes(dataNodes);
+            } else {
+                final Collection<String> cmHandleIdsToRetain = collectCmHandleIdsFromDataNodes(dataNodes);
+                cmHandleIds.retainAll(cmHandleIdsToRetain);
+            }
+            if (cmHandleIds.isEmpty()) {
+                break;
             }
         }
-        final Set<NcmpServiceCmHandle> ncmpServiceCmHandles = new HashSet<>(cmHandleAsDataNodePerCmHandleId.size());
-        cmHandleAsDataNodePerCmHandleId.values().forEach(
-                cmHandleAsDataNode -> ncmpServiceCmHandles.add(createNcmpServiceCmHandle(cmHandleAsDataNode)));
-        return ncmpServiceCmHandles;
+        return cmHandleIds;
     }
 
     private List<DataNode> getCmHandlesByDmiPluginIdentifierAndDmiProperty(final String dmiPluginIdentifier,