diff --git a/cps-ri/src/main/java/org/onap/cps/spi/entities/SchemaSet.java b/cps-ri/src/main/java/org/onap/cps/spi/entities/SchemaSet.java
new file mode 100644
index 0000000..fe67a60
--- /dev/null
+++ b/cps-ri/src/main/java/org/onap/cps/spi/entities/SchemaSet.java
@@ -0,0 +1,71 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Pantheon.tech
+ *  ================================================================================
+ *  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.spi.entities;
+
+import java.io.Serializable;
+import java.util.Set;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.JoinColumn;
+import javax.persistence.JoinTable;
+import javax.persistence.ManyToMany;
+import javax.persistence.ManyToOne;
+import javax.persistence.Table;
+import javax.validation.constraints.NotNull;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+/**
+ * Entity to store a Schema Set.
+ */
+@Getter
+@Setter
+@NoArgsConstructor
+@Entity
+@Table(name = "schema_set")
+public class SchemaSet implements Serializable {
+
+    private static final long serialVersionUID = 6665056955069047269L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Integer id;
+
+    @NotNull
+    @Column
+    private String name;
+
+    @NotNull
+    @ManyToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "dataspace_id", referencedColumnName = "ID")
+    private Dataspace dataspace;
+
+    @NotNull
+    @ManyToMany(fetch = FetchType.LAZY)
+    @JoinTable(name = "schema_set_yang_resources",
+        joinColumns = @JoinColumn(name = "schema_set_id"),
+        inverseJoinColumns = @JoinColumn(name = "yang_resource_id"))
+    private Set<YangResource> yangResources;
+}
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/entities/YangResource.java b/cps-ri/src/main/java/org/onap/cps/spi/entities/YangResource.java
new file mode 100644
index 0000000..862b7ae
--- /dev/null
+++ b/cps-ri/src/main/java/org/onap/cps/spi/entities/YangResource.java
@@ -0,0 +1,63 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Pantheon.tech
+ *  ================================================================================
+ *  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.spi.entities;
+
+import java.io.Serializable;
+import java.util.Set;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToMany;
+import javax.persistence.Table;
+import javax.validation.constraints.NotNull;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+/**
+ * Entity to store a Yang files.
+ */
+@Getter
+@Setter
+@NoArgsConstructor
+@Entity
+@Table(name = "yang_resource")
+public class YangResource implements Serializable {
+
+    private static final long serialVersionUID = -4496883162142106774L;
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @NotNull
+    @Column
+    private String checksum;
+
+    @NotNull
+    @Column
+    private String content;
+
+    @ManyToMany(mappedBy = "yangResources")
+    private Set<SchemaSet> moduleSets;
+
+}
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/impl/ModelPersistenceServiceImpl.java b/cps-ri/src/main/java/org/onap/cps/spi/impl/ModelPersistenceServiceImpl.java
index 03679b3..2207f79 100755
--- a/cps-ri/src/main/java/org/onap/cps/spi/impl/ModelPersistenceServiceImpl.java
+++ b/cps-ri/src/main/java/org/onap/cps/spi/impl/ModelPersistenceServiceImpl.java
@@ -20,39 +20,92 @@
 
 package org.onap.cps.spi.impl;
 
-import org.onap.cps.exceptions.CpsValidationException;
+import static org.onap.cps.exceptions.CpsExceptionBuilder.duplicateSchemaSetException;
+import static org.onap.cps.exceptions.CpsExceptionBuilder.invalidDataspaceException;
+
+import com.google.common.collect.ImmutableSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
+import javax.transaction.Transactional;
 import org.onap.cps.spi.ModelPersistenceService;
 import org.onap.cps.spi.entities.Dataspace;
-import org.onap.cps.spi.entities.Module;
+import org.onap.cps.spi.entities.SchemaSet;
+import org.onap.cps.spi.entities.YangResource;
 import org.onap.cps.spi.repository.DataspaceRepository;
-import org.onap.cps.spi.repository.ModuleRepository;
+import org.onap.cps.spi.repository.SchemaSetRepository;
+import org.onap.cps.spi.repository.YangResourceRepository;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.dao.DataIntegrityViolationException;
 import org.springframework.stereotype.Component;
+import org.springframework.util.DigestUtils;
 
 @Component
 public class ModelPersistenceServiceImpl implements ModelPersistenceService {
 
     @Autowired
-    private ModuleRepository moduleRepository;
+    private YangResourceRepository yangResourceRepository;
+
+    @Autowired
+    private SchemaSetRepository schemaSetRepository;
 
     @Autowired
     private DataspaceRepository dataspaceRepository;
 
     @Override
     public void storeModule(final String namespace, final String moduleContent, final String revision,
-        final String dataspaceName) {
-        final Dataspace dataspace = new Dataspace(dataspaceName);
-        if (Boolean.FALSE.equals(dataspaceRepository.existsByName(dataspaceName))) {
-            dataspaceRepository.save(dataspace);
-        }
-        dataspace.setId(dataspaceRepository.getByName(dataspaceName).getId());
-        final Module module = new Module(namespace, moduleContent, revision, dataspace);
+                            final String dataspaceName) {
+        // TODO this method should be removed as obsolete.
+        // Modules to be processed within schema sets only.
+    }
+
+    @Override
+    @Transactional
+    public void storeSchemaSet(final String dataspaceName, final String schemaSetName,
+                               final Set<String> yangResourcesAsStrings) {
+
+        final Dataspace dataspace = dataspaceRepository.findByName(dataspaceName)
+            .orElseThrow(() -> invalidDataspaceException(dataspaceName));
+
+        final Set<YangResource> yangResources = synchronizeYangResources(yangResourcesAsStrings);
+        final SchemaSet schemaSet = new SchemaSet();
+        schemaSet.setName(schemaSetName);
+        schemaSet.setDataspace(dataspace);
+        schemaSet.setYangResources(yangResources);
         try {
-            moduleRepository.save(module);
-        } catch (final DataIntegrityViolationException ex) {
-            throw new CpsValidationException("Duplicate Entry",
-                String.format("Module already exist in dataspace %s.", dataspaceName));
+            schemaSetRepository.save(schemaSet);
+        } catch (final DataIntegrityViolationException e) {
+            throw duplicateSchemaSetException(dataspaceName, schemaSetName);
         }
     }
+
+    private Set<YangResource> synchronizeYangResources(final Set<String> yangResourcesAsStrings) {
+        final Map<String, String> checksumToContentMap = yangResourcesAsStrings.stream()
+            .collect(Collectors.toMap(
+                content -> DigestUtils.md5DigestAsHex(content.getBytes()),
+                content -> content)
+            );
+
+        final List<YangResource> existingYangResources =
+            yangResourceRepository.findAllByChecksumIn(checksumToContentMap.keySet());
+        existingYangResources.forEach(yangFile -> checksumToContentMap.remove(yangFile.getChecksum()));
+
+        final List<YangResource> newYangResources = checksumToContentMap.entrySet().stream()
+            .map(entry -> {
+                final YangResource yangResource = new YangResource();
+                yangResource.setChecksum(entry.getKey());
+                yangResource.setContent(entry.getValue());
+                return yangResource;
+            }).collect(Collectors.toList());
+        if (!newYangResources.isEmpty()) {
+            yangResourceRepository.saveAll(newYangResources);
+        }
+
+        return ImmutableSet.<YangResource>builder()
+            .addAll(existingYangResources)
+            .addAll(newYangResources)
+            .build();
+    }
+
 }
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/repository/SchemaSetRepository.java b/cps-ri/src/main/java/org/onap/cps/spi/repository/SchemaSetRepository.java
new file mode 100644
index 0000000..f974697
--- /dev/null
+++ b/cps-ri/src/main/java/org/onap/cps/spi/repository/SchemaSetRepository.java
@@ -0,0 +1,36 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Pantheon.tech
+ *  ================================================================================
+ *  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.spi.repository;
+
+import java.util.List;
+import java.util.Optional;
+import javax.validation.constraints.NotNull;
+import org.onap.cps.spi.entities.Dataspace;
+import org.onap.cps.spi.entities.SchemaSet;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface SchemaSetRepository extends JpaRepository<SchemaSet, Integer> {
+
+    List<SchemaSet> findAllByDataspace(@NotNull Dataspace dataspace);
+
+    Optional<SchemaSet> findByDataspaceAndName(@NotNull Dataspace dataspace, @NotNull String name);
+}
diff --git a/cps-ri/src/main/java/org/onap/cps/spi/repository/YangResourceRepository.java b/cps-ri/src/main/java/org/onap/cps/spi/repository/YangResourceRepository.java
new file mode 100644
index 0000000..47d3ea3
--- /dev/null
+++ b/cps-ri/src/main/java/org/onap/cps/spi/repository/YangResourceRepository.java
@@ -0,0 +1,34 @@
+/*
+ *  ============LICENSE_START=======================================================
+ *  Copyright (C) 2020 Pantheon.tech
+ *  ================================================================================
+ *  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.spi.repository;
+
+import java.util.List;
+import java.util.Set;
+import javax.validation.constraints.NotNull;
+import org.onap.cps.spi.entities.YangResource;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface YangResourceRepository extends JpaRepository<YangResource, Long> {
+
+    List<YangResource> findAllByChecksumIn(@NotNull Set<String> checksum);
+
+}
diff --git a/cps-ri/src/main/resources/schema.sql b/cps-ri/src/main/resources/schema.sql
index 3fabc6c..d47f261 100755
--- a/cps-ri/src/main/resources/schema.sql
+++ b/cps-ri/src/main/resources/schema.sql
@@ -17,6 +17,30 @@
     ID SERIAL PRIMARY KEY
 );
 
+CREATE TABLE IF NOT EXISTS SCHEMA_SET
+(
+    ID SERIAL PRIMARY KEY,
+    NAME TEXT NOT NULL,
+    DATASPACE_ID BIGINT NOT NULL,
+    UNIQUE (NAME, DATASPACE_ID),
+    CONSTRAINT SCHEMA_SET_DATASPACE FOREIGN KEY (DATASPACE_ID) REFERENCES DATASPACE(ID) ON UPDATE CASCADE ON DELETE CASCADE
+);
+
+CREATE TABLE IF NOT EXISTS YANG_RESOURCE
+(
+    ID SERIAL PRIMARY KEY,
+    CHECKSUM TEXT NOT NULL,
+    CONTENT TEXT NOT NULL,
+    UNIQUE (CHECKSUM)
+);
+
+CREATE TABLE IF NOT EXISTS SCHEMA_SET_YANG_RESOURCES
+(
+    SCHEMA_SET_ID BIGINT NOT NULL,
+    YANG_RESOURCE_ID BIGINT NOT NULL REFERENCES YANG_RESOURCE(ID),
+    CONSTRAINT SCHEMA_SET_RESOURCE FOREIGN KEY (SCHEMA_SET_ID) REFERENCES SCHEMA_SET(ID) ON DELETE CASCADE
+);
+
 CREATE TABLE IF NOT EXISTS MODULE
 (
     ID SERIAL PRIMARY KEY,
@@ -62,4 +86,4 @@
 CREATE INDEX  IF NOT EXISTS "FKI_RELATIONS_FROM_ID_FK"         ON RELATION USING BTREE(FROM_FRAGMENT_ID);
 CREATE INDEX  IF NOT EXISTS "FKI_RELATIONS_TO_ID_FK"           ON RELATION USING BTREE(TO_FRAGMENT_ID);
 CREATE INDEX  IF NOT EXISTS "PERF_MODULE_MODULE_CONTENT"       ON MODULE USING BTREE(MODULE_CONTENT);
-CREATE UNIQUE INDEX  IF NOT EXISTS "UQ_FRAGMENT_XPATH"ON FRAGMENT USING btree(xpath COLLATE pg_catalog."default" text_pattern_ops, dataspace_id);
\ No newline at end of file
+CREATE UNIQUE INDEX  IF NOT EXISTS "UQ_FRAGMENT_XPATH"ON FRAGMENT USING btree(xpath COLLATE pg_catalog."default" text_pattern_ops, dataspace_id);