String primaryKeyName = getTablePrimaryKeyName(tableName);
synchronized (table) {
for (Map<String,Object> updateRow : updateRowList) {
Object rowKey = updateRow.get(primaryKeyName);
if (rowKey == null)
throw new StorageException("Primary key not found.");
Map<String,Object> row = table.getRow(rowKey);
if (row == null)
row = table.newRow(rowKey);
for (Map.Entry<String,Object> entry: updateRow.entrySet()) {
row.put(entry.getKey(), entry.getValue());