/// <summary>
        /// Enumerate all internal changes, no batch mode
        /// </summary>
        internal async Task <(BatchInfo, ChangesSelected)> EnumerateChangesInBatchesInternal
            (SyncContext context, ScopeInfo scopeInfo, int downloadBatchSizeInKB, DmSet configTables, string batchDirectory, ConflictResolutionPolicy policy, ICollection <FilterClause> filters)
        {
            DmTable dmTable = null;
            // memory size total
            double memorySizeFromDmRows = 0L;

            int batchIndex = 0;

            // this batch info won't be in memory, it will be be batched
            BatchInfo batchInfo = new BatchInfo
            {
                // directory where all files will be stored
                Directory = BatchInfo.GenerateNewDirectoryName(),
                // not in memory since we serialized all files in the tmp directory
                InMemory = false
            };

            // Create stats object to store changes count
            ChangesSelected changes = new ChangesSelected();

            using (var connection = this.CreateConnection())
            {
                try
                {
                    // Open the connection
                    await connection.OpenAsync();

                    using (var transaction = connection.BeginTransaction())
                    {
                        // create the in memory changes set
                        DmSet changesSet = new DmSet(configTables.DmSetName);

                        foreach (var tableDescription in configTables.Tables)
                        {
                            // if we are in upload stage, so check if table is not download only
                            if (context.SyncWay == SyncWay.Upload && tableDescription.SyncDirection == SyncDirection.DownloadOnly)
                            {
                                continue;
                            }

                            // if we are in download stage, so check if table is not download only
                            if (context.SyncWay == SyncWay.Download && tableDescription.SyncDirection == SyncDirection.UploadOnly)
                            {
                                continue;
                            }

                            var builder     = this.GetDatabaseBuilder(tableDescription);
                            var syncAdapter = builder.CreateSyncAdapter(connection, transaction);
                            syncAdapter.ConflictApplyAction = SyncConfiguration.GetApplyAction(policy);

                            // raise before event
                            context.SyncStage = SyncStage.TableChangesSelecting;
                            var beforeArgs = new TableChangesSelectingEventArgs(this.ProviderTypeName, context.SyncStage, tableDescription.TableName);
                            this.TryRaiseProgressEvent(beforeArgs, this.TableChangesSelecting);

                            // Get Command
                            DbCommand     selectIncrementalChangesCommand;
                            DbCommandType dbCommandType;

                            if (this.CanBeServerProvider && context.Parameters != null && context.Parameters.Count > 0 && filters != null && filters.Count > 0)
                            {
                                var filtersName = filters
                                                  .Where(f => f.TableName.Equals(tableDescription.TableName, StringComparison.InvariantCultureIgnoreCase))
                                                  .Select(f => f.ColumnName);

                                if (filtersName != null && filtersName.Count() > 0)
                                {
                                    dbCommandType = DbCommandType.SelectChangesWitFilters;
                                    selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType, filtersName);
                                }
                                else
                                {
                                    dbCommandType = DbCommandType.SelectChanges;
                                    selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType);
                                }
                            }
                            else
                            {
                                dbCommandType = DbCommandType.SelectChanges;
                                selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType);
                            }

                            // Deriving Parameters
                            syncAdapter.SetCommandParameters(DbCommandType.SelectChanges, selectIncrementalChangesCommand);

                            if (selectIncrementalChangesCommand == null)
                            {
                                var exc = "Missing command 'SelectIncrementalChangesCommand' ";
                                throw new Exception(exc);
                            }

                            dmTable = BuildChangesTable(tableDescription.TableName, configTables);

                            try
                            {
                                // Set commons parameters
                                SetSelectChangesCommonParameters(context, scopeInfo, selectIncrementalChangesCommand);

                                // Set filter parameters if any
                                // Only on server side
                                if (this.CanBeServerProvider && context.Parameters != null && context.Parameters.Count > 0 && filters != null && filters.Count > 0)
                                {
                                    var filterTable = filters.Where(f => f.TableName.Equals(tableDescription.TableName, StringComparison.InvariantCultureIgnoreCase)).ToList();

                                    if (filterTable != null && filterTable.Count > 0)
                                    {
                                        foreach (var filter in filterTable)
                                        {
                                            var parameter = context.Parameters.FirstOrDefault(p => p.ColumnName.Equals(filter.ColumnName, StringComparison.InvariantCultureIgnoreCase) && p.TableName.Equals(filter.TableName, StringComparison.InvariantCultureIgnoreCase));

                                            if (parameter != null)
                                            {
                                                DbManager.SetParameterValue(selectIncrementalChangesCommand, parameter.ColumnName, parameter.Value);
                                            }
                                        }
                                    }
                                }

                                this.AddTrackingColumns <int>(dmTable, "sync_row_is_tombstone");

                                // Statistics
                                TableChangesSelected tableChangesSelected = new TableChangesSelected
                                {
                                    TableName = tableDescription.TableName
                                };

                                changes.TableChangesSelected.Add(tableChangesSelected);

                                // Get the reader
                                using (var dataReader = selectIncrementalChangesCommand.ExecuteReader())
                                {
                                    while (dataReader.Read())
                                    {
                                        DmRow dmRow = CreateRowFromReader(dataReader, dmTable);

                                        DmRowState state = DmRowState.Unchanged;

                                        state = GetStateFromDmRow(dmRow, scopeInfo);

                                        // If the row is not deleted inserted or modified, go next
                                        if (state != DmRowState.Deleted && state != DmRowState.Modified && state != DmRowState.Added)
                                        {
                                            continue;
                                        }

                                        var fieldsSize = DmTableSurrogate.GetRowSizeFromDataRow(dmRow);
                                        var dmRowSize  = fieldsSize / 1024d;

                                        if (dmRowSize > downloadBatchSizeInKB)
                                        {
                                            var exc = $"Row is too big ({dmRowSize} kb.) for the current Configuration.DownloadBatchSizeInKB ({downloadBatchSizeInKB} kb.) Aborting Sync...";
                                            throw new Exception(exc);
                                        }

                                        // Calculate the new memory size
                                        memorySizeFromDmRows = memorySizeFromDmRows + dmRowSize;

                                        // add row
                                        dmTable.Rows.Add(dmRow);
                                        tableChangesSelected.TotalChanges++;

                                        // acceptchanges before modifying
                                        dmRow.AcceptChanges();

                                        // Set the correct state to be applied
                                        if (state == DmRowState.Deleted)
                                        {
                                            dmRow.Delete();
                                            tableChangesSelected.Deletes++;
                                        }
                                        else if (state == DmRowState.Added)
                                        {
                                            dmRow.SetAdded();
                                            tableChangesSelected.Inserts++;
                                        }
                                        else if (state == DmRowState.Modified)
                                        {
                                            dmRow.SetModified();
                                            tableChangesSelected.Updates++;
                                        }

                                        // We exceed the memorySize, so we can add it to a batch
                                        if (memorySizeFromDmRows > downloadBatchSizeInKB)
                                        {
                                            // Since we dont need this column anymore, remove it
                                            this.RemoveTrackingColumns(dmTable, "sync_row_is_tombstone");

                                            changesSet.Tables.Add(dmTable);

                                            // generate the batch part info
                                            batchInfo.GenerateBatchInfo(batchIndex, changesSet, batchDirectory);

                                            // increment batch index
                                            batchIndex++;

                                            changesSet.Clear();

                                            // Recreate an empty DmSet, then a dmTable clone
                                            changesSet = new DmSet(configTables.DmSetName);
                                            dmTable    = dmTable.Clone();
                                            this.AddTrackingColumns <int>(dmTable, "sync_row_is_tombstone");

                                            // Init the row memory size
                                            memorySizeFromDmRows = 0L;

                                            // add stats for a SyncProgress event
                                            context.SyncStage = SyncStage.TableChangesSelected;
                                            var args2 = new TableChangesSelectedEventArgs
                                                            (this.ProviderTypeName, SyncStage.TableChangesSelected, tableChangesSelected);

                                            this.TryRaiseProgressEvent(args2, this.TableChangesSelected);
                                        }
                                    }

                                    // Since we dont need this column anymore, remove it
                                    this.RemoveTrackingColumns(dmTable, "sync_row_is_tombstone");

                                    context.SyncStage = SyncStage.TableChangesSelected;

                                    changesSet.Tables.Add(dmTable);

                                    // Init the row memory size
                                    memorySizeFromDmRows = 0L;

                                    // Event progress
                                    context.SyncStage = SyncStage.TableChangesSelected;
                                    var args = new TableChangesSelectedEventArgs(this.ProviderTypeName, SyncStage.TableChangesSelected, tableChangesSelected);
                                    this.TryRaiseProgressEvent(args, this.TableChangesSelected);
                                }
                            }
                            catch (Exception)
                            {
                                throw;
                            }
                            finally
                            {
                            }
                        }

                        // We are in batch mode, and we are at the last batchpart info
                        if (changesSet != null && changesSet.HasTables && changesSet.HasChanges())
                        {
                            var batchPartInfo = batchInfo.GenerateBatchInfo(batchIndex, changesSet, batchDirectory);

                            if (batchPartInfo != null)
                            {
                                batchPartInfo.IsLastBatch = true;
                            }
                        }

                        transaction.Commit();
                    }
                }
                catch (Exception)
                {
                    throw;
                }
                finally
                {
                    if (connection != null && connection.State == ConnectionState.Open)
                    {
                        connection.Close();
                    }
                }
            }

            return(batchInfo, changes);
        }
        /// <summary>
        /// Enumerate all internal changes, no batch mode
        /// </summary>
        internal async Task <(BatchInfo, ChangesSelected)> EnumerateChangesInternal(
            SyncContext context, ScopeInfo scopeInfo, DmSet configTables, string batchDirectory, ConflictResolutionPolicy policy, ICollection <FilterClause> filters)
        {
            // create the in memory changes set
            DmSet changesSet = new DmSet(SyncConfiguration.DMSET_NAME);

            // Create the batch info, in memory
            var batchInfo = new BatchInfo
            {
                InMemory = true
            };

            using (var connection = this.CreateConnection())
            {
                // Open the connection
                await connection.OpenAsync();

                using (var transaction = connection.BeginTransaction())
                {
                    try
                    {
                        // changes that will be returned as selected changes
                        ChangesSelected changes = new ChangesSelected();

                        foreach (var tableDescription in configTables.Tables)
                        {
                            // if we are in upload stage, so check if table is not download only
                            if (context.SyncWay == SyncWay.Upload && tableDescription.SyncDirection == SyncDirection.DownloadOnly)
                            {
                                continue;
                            }

                            // if we are in download stage, so check if table is not download only
                            if (context.SyncWay == SyncWay.Download && tableDescription.SyncDirection == SyncDirection.UploadOnly)
                            {
                                continue;
                            }

                            var builder     = this.GetDatabaseBuilder(tableDescription);
                            var syncAdapter = builder.CreateSyncAdapter(connection, transaction);
                            syncAdapter.ConflictApplyAction = SyncConfiguration.GetApplyAction(policy);

                            // raise before event
                            context.SyncStage = SyncStage.TableChangesSelecting;
                            var beforeArgs = new TableChangesSelectingEventArgs(this.ProviderTypeName, context.SyncStage, tableDescription.TableName);
                            this.TryRaiseProgressEvent(beforeArgs, this.TableChangesSelecting);

                            // selected changes for the current table
                            TableChangesSelected tableSelectedChanges = new TableChangesSelected
                            {
                                TableName = tableDescription.TableName
                            };

                            // Get Command
                            DbCommand     selectIncrementalChangesCommand;
                            DbCommandType dbCommandType;

                            if (this.CanBeServerProvider && context.Parameters != null && context.Parameters.Count > 0 && filters != null && filters.Count > 0)
                            {
                                var filtersName = filters
                                                  .Where(f => f.TableName.Equals(tableDescription.TableName, StringComparison.InvariantCultureIgnoreCase))
                                                  .Select(f => f.ColumnName);

                                if (filtersName != null && filtersName.Count() > 0)
                                {
                                    dbCommandType = DbCommandType.SelectChangesWitFilters;
                                    selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType, filtersName);
                                }
                                else
                                {
                                    dbCommandType = DbCommandType.SelectChanges;
                                    selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType);
                                }
                            }
                            else
                            {
                                dbCommandType = DbCommandType.SelectChanges;
                                selectIncrementalChangesCommand = syncAdapter.GetCommand(dbCommandType);
                            }

                            if (selectIncrementalChangesCommand == null)
                            {
                                var exc = "Missing command 'SelectIncrementalChangesCommand' ";
                                throw new Exception(exc);
                            }

                            // Deriving Parameters
                            syncAdapter.SetCommandParameters(dbCommandType, selectIncrementalChangesCommand);

                            // Get a clone of the table with tracking columns
                            var dmTableChanges = BuildChangesTable(tableDescription.TableName, configTables);

                            SetSelectChangesCommonParameters(context, scopeInfo, selectIncrementalChangesCommand);

                            // Set filter parameters if any
                            if (this.CanBeServerProvider && context.Parameters != null && context.Parameters.Count > 0 && filters != null && filters.Count > 0)
                            {
                                var tableFilters = filters.Where(f => f.TableName.Equals(tableDescription.TableName, StringComparison.InvariantCultureIgnoreCase)).ToList();

                                if (tableFilters != null && tableFilters.Count > 0)
                                {
                                    foreach (var filter in tableFilters)
                                    {
                                        var parameter = context.Parameters.FirstOrDefault(p => p.ColumnName.Equals(filter.ColumnName, StringComparison.InvariantCultureIgnoreCase) && p.TableName.Equals(filter.TableName, StringComparison.InvariantCultureIgnoreCase));

                                        if (parameter != null)
                                        {
                                            DbManager.SetParameterValue(selectIncrementalChangesCommand, parameter.ColumnName, parameter.Value);
                                        }
                                    }
                                }
                            }

                            this.AddTrackingColumns <int>(dmTableChanges, "sync_row_is_tombstone");

                            // Get the reader
                            using (var dataReader = selectIncrementalChangesCommand.ExecuteReader())
                            {
                                while (dataReader.Read())
                                {
                                    DmRow dataRow = CreateRowFromReader(dataReader, dmTableChanges);

                                    //DmRow dataRow = dmTableChanges.NewRow();

                                    // assuming the row is not inserted / modified
                                    DmRowState state = DmRowState.Unchanged;

                                    // get if the current row is inserted, modified, deleted
                                    state = GetStateFromDmRow(dataRow, scopeInfo);

                                    if (state != DmRowState.Deleted && state != DmRowState.Modified && state != DmRowState.Added)
                                    {
                                        continue;
                                    }

                                    // add row
                                    dmTableChanges.Rows.Add(dataRow);

                                    // acceptchanges before modifying
                                    dataRow.AcceptChanges();
                                    tableSelectedChanges.TotalChanges++;

                                    // Set the correct state to be applied
                                    if (state == DmRowState.Deleted)
                                    {
                                        dataRow.Delete();
                                        tableSelectedChanges.Deletes++;
                                    }
                                    else if (state == DmRowState.Added)
                                    {
                                        dataRow.SetAdded();
                                        tableSelectedChanges.Inserts++;
                                    }
                                    else if (state == DmRowState.Modified)
                                    {
                                        dataRow.SetModified();
                                        tableSelectedChanges.Updates++;
                                    }
                                }

                                // Since we dont need this column anymore, remove it
                                this.RemoveTrackingColumns(dmTableChanges, "sync_row_is_tombstone");

                                // add it to the DmSet
                                changesSet.Tables.Add(dmTableChanges);
                            }

                            // add the stats to global stats
                            changes.TableChangesSelected.Add(tableSelectedChanges);

                            // Raise event for this table
                            context.SyncStage = SyncStage.TableChangesSelected;
                            var args = new TableChangesSelectedEventArgs(this.ProviderTypeName, SyncStage.TableChangesSelected, tableSelectedChanges);
                            this.TryRaiseProgressEvent(args, this.TableChangesSelected);
                        }


                        transaction.Commit();

                        // generate the batchpartinfo
                        batchInfo.GenerateBatchInfo(0, changesSet, batchDirectory);

                        // Create a new in-memory batch info with an the changes DmSet
                        return(batchInfo, changes);
                    }
                    catch (Exception)
                    {
                        throw;
                    }
                    finally
                    {
                        if (connection != null && connection.State == ConnectionState.Open)
                        {
                            connection.Close();
                        }
                    }
                }
            }
        }