--- a/OrthancServer/Plugins/Include/orthanc/OrthancCPlugin.h	Mon Mar 27 16:50:48 2023 +0200
+++ b/OrthancServer/Plugins/Include/orthanc/OrthancCPlugin.h	Mon Mar 27 21:18:37 2023 +0200
@@ -17,7 +17,7 @@
  *    - Possibly register its callback for received DICOM instances using ::OrthancPluginRegisterOnStoredInstanceCallback().
  *    - Possibly register its callback for changes to the DICOM store using ::OrthancPluginRegisterOnChangeCallback().
  *    - Possibly register a custom storage area using ::OrthancPluginRegisterStorageArea2().
- *    - Possibly register a custom database back-end area using OrthancPluginRegisterDatabaseBackendV3().
+ *    - Possibly register a custom database back-end area using OrthancPluginRegisterDatabaseBackendV4().
  *    - Possibly register a handler for C-Find SCP using OrthancPluginRegisterFindCallback().
  *    - Possibly register a handler for C-Find SCP against DICOM worklists using OrthancPluginRegisterWorklistCallback().
  *    - Possibly register a handler for C-Move SCP using OrthancPluginRegisterMoveCallback().
@@ -535,7 +535,8 @@
     _OrthancPluginService_StorageAreaRead = 5004,
     _OrthancPluginService_StorageAreaRemove = 5005,
     _OrthancPluginService_RegisterDatabaseBackendV3 = 5006,  /* New in Orthanc 1.9.2 */
-
+    _OrthancPluginService_RegisterDatabaseBackendV4 = 5007,  /* New in Orthanc 1.11.4 */
+    
     /* Primitives for handling images */
     _OrthancPluginService_GetImagePixelFormat = 6000,
     _OrthancPluginService_GetImageWidth = 6001,
@@ -9164,6 +9165,53 @@
   }
 
 
+  /**
+   * @brief 
+   * @ingroup Callbacks
+   **/
+  typedef OrthancPluginErrorCode (*OrthancPluginCallDatabaseBackendV4) (
+    OrthancPluginMemoryBuffer64* response,
+    void* backend,
+    const void* request,
+    uint64_t requestSize);
+
+  /**
+   * @brief 
+   * @ingroup Callbacks
+   **/
+  typedef void (*OrthancPluginFinalizeDatabaseBackendV4) (void* backend);
+
+  typedef struct
+  {
+    void*                                   backend;
+    OrthancPluginCallDatabaseBackendV4      operations;
+    OrthancPluginFinalizeDatabaseBackendV4  finalize;
+  } _OrthancPluginRegisterDatabaseBackendV4;
+
+  /**
+   * Register a custom database back-end.
+   *
+   * @param context The Orthanc plugin context, as received by OrthancPluginInitialize().
+   * @param operations Access to the operations of the custom database backend.
+   * @param finalize Callback to deallocate the custom database backend.
+   * @param backend Pointer to the custom database backend.
+   * @return 0 if success, other value if error.
+   * @ingroup Callbacks
+   **/
+  ORTHANC_PLUGIN_INLINE OrthancPluginErrorCode OrthancPluginRegisterDatabaseBackendV4(
+    OrthancPluginContext*                   context,
+    void*                                   backend,
+    OrthancPluginCallDatabaseBackendV4      operations,
+    OrthancPluginFinalizeDatabaseBackendV4  finalize)
+  {
+    _OrthancPluginRegisterDatabaseBackendV4 params;
+    params.backend = backend;
+    params.operations = operations;
+    params.finalize = finalize;
+
+    return context->InvokeService(context, _OrthancPluginService_RegisterDatabaseBackendV4, &params);
+  }
+
 #ifdef  __cplusplus
 }
 #endif

--- a/OrthancServer/Plugins/Include/orthanc/OrthancDatabasePlugin.proto	Mon Mar 27 16:50:48 2023 +0200
+++ b/OrthancServer/Plugins/Include/orthanc/OrthancDatabasePlugin.proto	Mon Mar 27 21:18:37 2023 +0200
@@ -1,47 +1,213 @@
+/**
+ * Orthanc - A Lightweight, RESTful DICOM Store
+ * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+ * Department, University Hospital of Liege, Belgium
+ * Copyright (C) 2017-2023 Osimis S.A., Belgium
+ * Copyright (C) 2021-2023 Sebastien Jodogne, ICTEAM UCLouvain, Belgium
+ *
+ * This program is free software: you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ **/
+
+
 syntax = "proto3";
 
 package Orthanc.DatabasePluginMessages;
 
 
+/**
+ * Data structures that are common with the Orthanc core.
+ **/
+
 message FileInfo {
   string  uuid = 1;
   int32   content_type = 2;      // opaque "FileContentType" in Orthanc
-  uint64  uncompressedSize = 3;
-  string  uncompressedHash = 4;
-  int32   compression = 5;       // opaque "CompressionType" in Orthanc
-  uint64  compressedSize = 6;
-  string  compressedHash = 7;
+  uint64  uncompressed_size = 3;
+  string  uncompressed_hash = 4;
+  int32   compression_type = 5;  // opaque "CompressionType" in Orthanc
+  uint64  compressed_size = 6;
+  string  compressed_hash = 7;
+}
+
+enum ResourceType {
+  RESOURCE_PATIENT = 0;
+  RESOURCE_STUDY = 1;
+  RESOURCE_SERIES = 2;
+  RESOURCE_INSTANCE = 3;
+}
+
+enum ConstraintType {
+  CONSTRAINT_EQUAL = 0;
+  CONSTRAINT_SMALLER_OR_EQUAL = 1;
+  CONSTRAINT_GREATER_OR_EQUAL = 2;
+  CONSTRAINT_WILDCARD = 3;
+  CONSTRAINT_LIST = 4;
+}
+
+message ServerIndexChange {
+  int64         seq = 1;
+  int32         change_type = 2;   // opaque "ChangeType" in Orthanc
+  ResourceType  resource_type = 3;
+  string        public_id = 4;
+  string        date = 5;
+}
+
+message ExportedResource {
+  int64         seq = 1;
+  ResourceType  resource_type = 2;
+  string        public_id = 3;
+  string        modality = 4;
+  string        date = 5;
+  string        patient_id = 6;
+  string        study_instance_uid = 7;
+  string        series_instance_uid = 8;
+  string        sop_instance_uid = 9;
+}
+
+message DatabaseConstraint {
+  ResourceType     level = 1;
+  int32            tag = 2;
+  string           value = 3;
+  bool             is_identifier = 4;
+  ConstraintType   constraint = 5;
+  repeated string  values = 6;
+  bool             case_sensitive = 7;
+  bool             mandatory = 8;
 }
 
 
 /**
- * Database-level operations
+ * Database-level operations.
  **/
 
 enum DatabaseOperation {
   OPERATION_OPEN = 0;
   OPERATION_CLOSE = 1;
+  OPERATION_FLUSH_TO_DISK = 2;
+  OPERATION_HAS_FLUSH_TO_DISK = 3;
+  OPERATION_START_TRANSACTION = 4;
+  OPERATION_GET_DATABASE_VERSION = 5;
+  OPERATION_UPGRADE = 6;
+  OPERATION_HAS_REVISION_SUPPORT = 7;
 }
 
+enum TransactionType {
+  TRANSACTION_TYPE_READ_ONLY = 0;
+  TRANSACTION_TYPE_READ_WRITE = 1;
+}
+
+message Open {
+  message Request {
+  }
+  message Response {
+  }
+}
+
+message Close {
+  message Request {
+  }
+  message Response {
+  }
+}
+
+message FlushToDisk {
+  message Request {
+  }
+  message Response {
+  }
+}
+
+message TestFlushToDisk {
+  message Request {
+  }
+  message Response {
+    bool result = 1;
+  }
+}
+
+message StartTransaction {
+  message Request {
+    TransactionType type = 1;
+  }
+  message Response {
+    sfixed64 transaction = 1;
+  }
+}
+
+message GetDatabaseVersion {
+  message Request {
+  }
+  message Response {
+    uint32 version = 1;
+  }
+}
+
+message Upgrade {
+  message Request {
+    uint32 targetVersion = 1;
+    sfixed64 storageArea = 2;
+  }
+  message Response {
+  }
+}
+
+message TestRevisionsSupport {
+  message Request {
+  }
+  message Response {
+    bool result = 1;
+  }
+}
+
+
 message RequestDatabase {
-  sfixed64          database = 1;
-  DatabaseOperation operation = 2;
+  sfixed64           database = 1;
+  DatabaseOperation  operation = 2;
+
+  Open.Request                  open = 100;
+  Close.Request                 close = 101;
+  FlushToDisk.Request           flush_to_disk = 102;
+  TestFlushToDisk.Request       test_flush_to_disk = 103;
+  StartTransaction.Request      start_transaction = 104;
+  GetDatabaseVersion.Request    get_database_version = 105;
+  Upgrade.Request               upgrade = 106;
+  TestRevisionsSupport.Request  test_revisions_support = 107;
 }
 
 message ResponseDatabase {
-  int32 error_code = 1;
+  int32   error_code = 1;
+  string  error_description = 2;
+
+  Open.Response                  open = 100;
+  Close.Response                 close = 101;
+  FlushToDisk.Response           flush_to_disk = 102;
+  TestFlushToDisk.Response       test_flush_to_disk = 103;
+  StartTransaction.Response      start_transaction = 104;
+  GetDatabaseVersion.Response    get_database_version = 105;
+  Upgrade.Response               upgrade = 106;
+  TestRevisionsSupport.Response  test_revisions_support = 107;
 }
 
 
 /**
- * Transaction-level operations
+ * Transaction-level operations.
  **/
 
 enum TransactionOperation {
   OPERATION_ROLLBACK = 0;
   OPERATION_COMMIT = 1;
   OPERATION_ADD_ATTACHMENT = 2;
-  OPERATION_OPERATION_CLEAR_CHANGES = 3;
+  OPERATION_CLEAR_CHANGES = 3;
   OPERATION_CLEAR_EXPORTED_RESOURCES = 4;
   OPERATION_DELETE_ATTACHMENT = 5;
   OPERATION_DELETE_METADATA = 6;
@@ -54,7 +220,7 @@
   OPERATION_GET_CHILDREN_PUBLIC_ID = 13;
   OPERATION_GET_EXPORTED_RESOURCES = 14;
   OPERATION_GET_LAST_CHANGE = 15;
-  OPERATION_GET_LAST_EXPORTEDRESOURCE = 16;
+  OPERATION_GET_LAST_EXPORTED_RESOURCE = 16;
   OPERATION_GET_MAIN_DICOM_TAGS = 17;
   OPERATION_GET_PUBLIC_ID = 18;
   OPERATION_GET_RESOURCES_COUNT = 19;
@@ -64,7 +230,7 @@
   OPERATION_IS_PROTECTED_PATIENT = 23;
   OPERATION_LIST_AVAILABLE_ATTACHMENTS = 24;
   OPERATION_LOG_CHANGE = 25;
-  OPERATION_LOG_EXPORTEDRESOURCE = 26;
+  OPERATION_LOG_EXPORTED_RESOURCE = 26;
   OPERATION_LOOKUP_ATTACHMENT = 27;
   OPERATION_LOOKUP_GLOBAL_PROPERTY = 28;
   OPERATION_LOOKUP_METADATA = 29;
@@ -77,7 +243,7 @@
   OPERATION_SET_METADATA = 36;
   OPERATION_SET_PROTECTED_PATIENT = 37;
   OPERATION_IS_DISK_SIZE_ABOVE = 38;
-  OPERATION_APPLY_LOOKUP_RESOURCES = 39;
+  OPERATION_LOOKUP_RESOURCES = 39;
   OPERATION_CREATE_INSTANCE = 40;
   OPERATION_SET_RESOURCES_CONTENT = 41;
   OPERATION_GET_CHILDREN_METADATA = 42;
@@ -117,31 +283,553 @@
   }
 }
 
+message ClearExportedResources {
+  message Request {
+  }
+  message Response {
+  }
+}
+
+message DeleteAttachment {
+  message Request {
+    int64 id = 1;
+    int32 type = 2;
+  }
+  message Response {
+    FileInfo deleted_attachment = 1;
+  }
+}
+
+message DeleteMetadata {
+  message Request {
+    int64 id = 1;
+    int32 type = 2;
+  }
+  message Response {
+  }
+}
+
+message DeleteResource {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    message Resource {
+      ResourceType level = 1;
+      string public_id = 2;
+    }
+    repeated FileInfo deleted_attachments = 1;
+    repeated Resource deleted_resources = 2;
+    bool is_remaining_ancestor = 3;
+    Resource remaining_ancestor = 4;
+  }
+}
+
+message GetAllMetadata {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    message Metadata {
+      int32 type = 1;
+      string value = 2;
+    }
+    repeated Metadata metadata = 1;
+  }
+}
+
 message GetAllPublicIds {
   message Request {
+    int32 resource_type = 1;
+  }
+  message Response {
+    repeated string ids = 1;
+  }
+}
+
+message GetAllPublicIdsWithLimits {
+  message Request {
+    int32  resource_type = 1;
+    uint64 since = 2;
+    uint32 limit = 3;
+  }
+  message Response {
+    repeated string ids = 1;
+  }
+}
+
+message GetChanges {
+  message Request {
+    uint64 since = 1;
+    uint32 limit = 2;
+  }
+  message Response {
+    repeated ServerIndexChange changes = 1;
+    bool done = 2;
+  }
+}
+
+message GetChildrenInternalId {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    repeated int64 ids = 1;
+  }
+}
+
+message GetChildrenPublicId {
+  message Request {
+    int64 id = 1;
   }
   message Response {
     repeated string ids = 1;
   }
 }
 
-message RequestTransaction {
-  sfixed64             transaction = 1;
-  TransactionOperation operation = 2;
+message GetExportedResources {
+  message Request {
+    int64 since = 1;
+    uint32 limit = 2;
+  }
+  message Response {
+    repeated ExportedResource resources = 1;
+    bool done = 2;
+  }
+}
+
+message GetLastChange {
+  message Request {
+  }
+  message Response {
+    bool is_empty = 1;
+    ServerIndexChange change = 2;
+  }
+}
+
+message GetLastExportedResource {
+  message Request {
+  }
+  message Response {
+    bool is_empty = 1;
+    ExportedResource resource = 2;
+  }
+}
+
+message GetMainDicomTags {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    message Tag {
+      uint32 key = 1;
+      string value = 2;
+    }
+    repeated Tag tags = 1;
+  }
+}
+
+message GetPublicId {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    string id = 1;
+  }
+}
+
+message GetResourcesCount {
+  message Request {
+    ResourceType type = 1;
+  }
+  message Response {
+    uint64 count = 1;
+  }
+}
+
+message GetResourceType {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    ResourceType type = 1;
+  }
+}
+
+message GetTotalCompressedSize {
+  message Request {
+  }
+  message Response {
+    uint64 size = 1;
+  }
+}
+
+message GetTotalUncompressedSize {
+  message Request {
+  }
+  message Response {
+    uint64 size = 1;
+  }
+}
+
+message IsProtectedPatient {
+  message Request {
+    int64 patient_id = 1;
+  }
+  message Response {
+    bool protected = 1;
+  }
+}
+
+message ListAvailableAttachments {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    repeated int32 attachments = 1;
+  }
+}
+
+message LogChange {
+  message Request {
+    int64 id = 1;
+    ServerIndexChange change = 2;
+  }
+  message Response {
+  }
+}
+
+message LogExportedResource {
+  message Request {
+    ExportedResource resource = 1;
+  }
+  message Response {
+  }
+}
+
+message LookupAttachment {
+  message Request {
+    int64 id = 1;
+    int32 content_type = 2;
+  }
+  message Response {
+    bool found = 1;
+    FileInfo attachment = 2;
+    int64 revision = 3;
+  }
+}
+
+message LookupGlobalProperty {
+  message Request {
+    int32 property = 1;
+    bool shared = 2;
+  }
+  message Response {
+    bool found = 1;
+    string value = 2;
+  }
+}
+
+message LookupMetadata {
+  message Request {
+    int64 id = 1;
+    int32 metadata_type = 2;
+  }
+  message Response {
+    bool found = 1;
+    string value = 2;
+    int64 revision = 3;
+  }
+}
+
+message LookupParent {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+    bool found = 1;
+    int64 parent = 2;
+  }
+}
+
+message LookupResource {
+  message Request {
+    string public_id = 1;
+  }
+  message Response {
+    bool found = 1;
+    int64 internal_id = 2;
+    ResourceType type = 3;
+  }
+}
+
+message SelectPatientToRecycle {
+  message Request {
+  }
+  message Response {
+    bool found = 1;
+    int64 id = 2;
+  }
+}
 
-  Rollback.Request         rollback = 100;
-  Commit.Request           commit = 101;
-  AddAttachment.Request    add_attachment = 102;
-  ClearChanges.Request     clear_changes = 103;
-  GetAllPublicIds.Request  get_all_public_ids = 1000;
+message SelectPatientToRecycleWithAvoid {
+  message Request {
+    int64 patient_id_to_avoid = 1;
+  }
+  message Response {
+    bool found = 1;
+    int64 id = 2;
+  }
+}
+
+message SetGlobalProperty {
+  message Request {
+    int32 property = 1;
+    bool shared = 2;
+    string value = 3;
+  }
+  message Response {
+  }
+}
+
+message ClearMainDicomTags {
+  message Request {
+    int64 id = 1;
+  }
+  message Response {
+  }
+}
+
+message SetMetadata {
+  message Request {
+    int64 id = 1;
+    int32 metadata_type = 2;
+    string value = 3;
+    int64 revision = 4;
+  }
+  message Response {
+  }
+}
+
+message SetProtectedPatient {
+  message Request {
+    int64 id = 1;
+    bool protected = 2;
+  }
+  message Response {
+  }
+}
+
+message IsDiskSizeAbove {
+  message Request {
+    uint64 threshold = 1;
+  }
+  message Response {
+    bool result = 1;
+  }
+}
+
+message LookupResources {
+  message Request {
+    repeated DatabaseConstraint lookup = 1;
+    ResourceType query_level = 2;
+    uint32 limit = 3;
+    bool retrieve_instances = 4;
+  }
+  message Response {
+    repeated string resources_ids = 1;
+    repeated string instances_ids = 2;  // Only filled if "retrieve_instances" is true
+  }
+}
+
+message CreateInstance {
+  message Request {
+    string patient = 1;
+    string study = 2;
+    string series = 3;
+    string instance = 4;
+  }
+  message Response {
+    bool is_new_instance = 1;
+    int64 instance_id = 2;
+
+    // The fields below are only set if "is_new_instance" is true
+    bool is_new_patient = 3;
+    bool is_new_study = 4;
+    bool is_new_series = 5;
+    int64 patient_id = 6;
+    int64 study_id = 7;
+    int64 series_id = 8;
+  }
+}
+
+message SetResourcesContent {
+  message Request {
+    message Tag {
+      int64 resource_id = 1;
+      bool is_identifier = 2;
+      uint32 key = 3;
+      string value = 4;
+    }
+
+    message Metadata {
+      int64 resource_id = 1;
+      int32 metadata = 2;
+      string value = 3;
+    }
+
+    bool is_new_resource = 1;
+    repeated Tag tags = 2;
+    repeated Metadata metadata = 3;
+  }
+  message Response {
+  }
+}
+
+message GetChildrenMetadata {
+  message Request {
+    int64 id = 1;
+    int32 metadata = 2;
+  }
+  message Response {
+    repeated string values = 1;
+  }
+}
+
+message GetLastChangeIndex {
+  message Request {
+  }
+  message Response {
+    int64 result = 1;
+  }
+}
+
+message LookupResourceAndParent {
+  message Request {
+    string public_id = 1;
+  }
+  message Response {
+    bool found = 1;
+    int64 id = 2;
+    ResourceType type = 3;
+    string parent_public_id = 4;
+  }
+}
+
+message RequestTransaction {
+  sfixed64              transaction = 1;
+  TransactionOperation  operation = 2;
+
+  Rollback.Request                        rollback = 100;
+  Commit.Request                          commit = 101;
+  AddAttachment.Request                   add_attachment = 102;
+  ClearChanges.Request                    clear_changes = 103;
+  ClearExportedResources.Request          clear_exported_resources = 104;
+  DeleteAttachment.Request                delete_attachment = 105;
+  DeleteMetadata.Request                  delete_metadata = 106;
+  DeleteResource.Request                  delete_resource = 107;
+  GetAllMetadata.Request                  get_all_metadata = 108;
+  GetAllPublicIds.Request                 get_all_public_ids = 109;
+  GetAllPublicIdsWithLimits.Request       get_all_public_ids_with_limits = 110;
+  GetChanges.Request                      get_changes = 111;
+  GetChildrenInternalId.Request           get_children_internal_id = 112;
+  GetChildrenPublicId.Request             get_children_public_id = 113;
+  GetExportedResources.Request            get_exported_resources = 114;
+  GetLastChange.Request                   get_last_change = 115;
+  GetLastExportedResource.Request         get_last_exported_resource = 116;
+  GetMainDicomTags.Request                get_main_dicom_tags = 117;
+  GetPublicId.Request                     get_public_id = 118;
+  GetResourcesCount.Request               get_resources_count = 119;
+  GetResourceType.Request                 get_resource_type = 120;
+  GetTotalCompressedSize.Request          get_total_compressed_size = 121;
+  GetTotalUncompressedSize.Request        get_total_uncompressed_size = 122;
+  IsProtectedPatient.Request              is_protected_patient = 123;
+  ListAvailableAttachments.Request        list_available_attachments = 124;
+  LogChange.Request                       log_change = 125;
+  LogExportedResource.Request             log_exported_resource = 126;
+  LookupAttachment.Request                lookup_attachment = 127;
+  LookupGlobalProperty.Request            lookup_global_property = 128;
+  LookupMetadata.Request                  lookup_metadata = 129;
+  LookupParent.Request                    lookup_parent = 130;
+  LookupResource.Request                  lookup_resource = 131;
+  SelectPatientToRecycle.Request          select_patient_to_recycle = 132;
+  SelectPatientToRecycleWithAvoid.Request select_patient_to_recycle_with_avoid = 133;
+  SetGlobalProperty.Request               set_global_property = 134;
+  ClearMainDicomTags.Request              clear_main_dicom_tags = 135;
+  SetMetadata.Request                     set_metadata = 136;
+  SetProtectedPatient.Request             set_protected_patient = 137;
+  IsDiskSizeAbove.Request                 is_disk_size_above = 138;
+  LookupResources.Request                 lookup_resources = 139;
+  CreateInstance.Request                  create_instance = 140;
+  SetResourcesContent.Request             set_resources_content = 141;
+  GetChildrenMetadata.Request             get_children_metadata = 142;
+  GetLastChangeIndex.Request              get_last_change_index = 143;
+  LookupResourceAndParent.Request         lookup_resource_and_parent = 144;
 }
 
 message ResponseTransaction {
-  int32 error_code = 1;
+  int32   error_code = 1;
+  string  error_description = 2;
 
-  Rollback.Response         rollback = 100;
-  Commit.Response           commit = 101;
-  AddAttachment.Response    add_attachment = 102;
-  ClearChanges.Response     clear_changes = 103;
-  GetAllPublicIds.Response  get_all_public_ids = 1000;
+  Rollback.Response                        rollback = 100;
+  Commit.Response                          commit = 101;
+  AddAttachment.Response                   add_attachment = 102;
+  ClearChanges.Response                    clear_changes = 103;
+  ClearExportedResources.Response          clear_exported_resources = 104;
+  DeleteAttachment.Response                delete_attachment = 105;
+  DeleteMetadata.Response                  delete_metadata = 106;
+  DeleteResource.Response                  delete_resource = 107;
+  GetAllMetadata.Response                  get_all_metadata = 108;
+  GetAllPublicIds.Response                 get_all_public_ids = 109;
+  GetAllPublicIdsWithLimits.Response       get_all_public_ids_with_limits = 110;
+  GetChanges.Response                      get_changes = 111;
+  GetChildrenInternalId.Response           get_children_internal_id = 112;
+  GetChildrenPublicId.Response             get_children_public_id = 113;
+  GetExportedResources.Response            get_exported_resources = 114;
+  GetLastChange.Response                   get_last_change = 115;
+  GetLastExportedResource.Response         get_last_exported_resource = 116;
+  GetMainDicomTags.Response                get_main_dicom_tags = 117;
+  GetPublicId.Response                     get_public_id = 118;
+  GetResourcesCount.Response               get_resources_count = 119;
+  GetResourceType.Response                 get_resource_type = 120;
+  GetTotalCompressedSize.Response          get_total_compressed_size = 121;
+  GetTotalUncompressedSize.Response        get_total_uncompressed_size = 122;
+  IsProtectedPatient.Response              is_protected_patient = 123;
+  ListAvailableAttachments.Response        list_available_attachments = 124;
+  LogChange.Response                       log_change = 125;
+  LogExportedResource.Response             log_exported_resource = 126;
+  LookupAttachment.Response                lookup_attachment = 127;
+  LookupGlobalProperty.Response            lookup_global_property = 128;
+  LookupMetadata.Response                  lookup_metadata = 129;
+  LookupParent.Response                    lookup_parent = 130;
+  LookupResource.Response                  lookup_resource = 131;
+  SelectPatientToRecycle.Response          select_patient_to_recycle = 132;
+  SelectPatientToRecycleWithAvoid.Response select_patient_to_recycle_with_avoid = 133;
+  SetGlobalProperty.Response               set_global_property = 134;
+  ClearMainDicomTags.Response              clear_main_dicom_tags = 135;
+  SetMetadata.Response                     set_metadata = 136;
+  SetProtectedPatient.Response             set_protected_patient = 137;
+  IsDiskSizeAbove.Response                 is_disk_size_above = 138;
+  LookupResources.Response                 lookup_resources = 139;
+  CreateInstance.Response                  create_instance = 140;
+  SetResourcesContent.Response             set_resources_content = 141;
+  GetChildrenMetadata.Response             get_children_metadata = 142;
+  GetLastChangeIndex.Response              get_last_change_index = 143;
+  LookupResourceAndParent.Response         lookup_resource_and_parent = 144;
 }
+
+enum RequestType {
+  REQUEST_DATABASE = 0;
+  REQUEST_TRANSACTION = 1;
+}
+
+message Request {
+  RequestType         type = 1;
+  RequestDatabase     request_database = 2;
+  RequestTransaction  request_transaction = 3;
+}
+
+message Response {
+  ResponseDatabase     response_database = 1;
+  ResponseTransaction  response_transaction = 2;
+}