--- 
+++ 
@@ -104,17 +104,16 @@
             filename = self._get_filename(graph, i)
             title = '%s %s' % (self.GRAPHS[graph]['title'], 'Total Top %i' % TOP_N_VALUES)
             imgs.append([{'title': title, 'filename':filename}])
-            if not self.exists(filename):
-                # Totals graphs
-                total_values = copy.copy(sorted_values[:TOP_N_VALUES])
-                for j, val in enumerate(total_values):
-                    if val[1] < sorted_values[0][1] * 0.01: # 0.01 to limit the size of smallest part of the pie
-                        total_values = sorted_values[:j]
-                        break
+            # Totals graphs
+            total_values = copy.copy(sorted_values[:TOP_N_VALUES])
+            for j, val in enumerate(total_values):
+                if val[1] < sorted_values[0][1] * 0.01: # 0.01 to limit the size of smallest part of the pie
+                    total_values = sorted_values[:j]
+                    break
 
-                values = [val[1] for val in total_values]
-                labels = ['%s %s' % (val[0], humanize(val[1], self.GRAPHS[graph]['counter_type'])) for val in total_values]
-                self._render_pie(values, labels, title, filename)
+            values = [val[1] for val in total_values]
+            labels = ['%s %s' % (val[0], humanize(val[1], self.GRAPHS[graph]['counter_type'])) for val in total_values]
+            self._render_pie(values, labels, title, filename)
 
             def grouped(iterable, n):
                 "s -> (s0,s1,s2,...sn-1), (sn,sn+1,sn+2,...s2n-1), (s2n,s2n+1,s2n+2,...s3n-1), ..."
@@ -126,8 +125,7 @@
                 filename = self._get_filename(graph + str(i), j)
                 title = '%s %s' % (self.GRAPHS[graph]['title'], 'All %i/%i' % (j + 1, len(groups)))
                 imgs[-1].append({'title': title, 'filename':filename})
-                if self.exists(filename):
-                    continue
+
                 _values = [val[1] for val in values]
                 labels = ['%s %s' % (val[0], humanize(val[1], self.GRAPHS[graph]['counter_type'])) for val in values]
                 self._render_pie(_values, labels, title, filename)

--- 
+++ 
@@ -6,8 +6,6 @@
 
 class DotFile(OutputFile):
     def render(self, gv_file):
-        if self.exists():
-            return
         cmd = ['dot', '-Tcmapx', '-o' + self.filename + '.map', '-Tpng', '-o' + self.filename, gv_file]
 
         try:

--- 
+++ 
@@ -45,74 +45,73 @@
     imgs = db_size.render()
 
     # Tables
-    if not gv_map.exists():
-        gv_map.add_header()
+    gv_map.add_header()
 
-        print('Building graphs')
-        for table in db.get_tables():
-            columns = db.get_columns(table)
-            sizes = db.get_table_size(table)
-            keys = db.get_table_keys(table)
-            indexes = db.get_table_index(table)
-            errors = db.get_table_errors(table)
-            gv_map.add_table(table, errors, sizes, keys, indexes, columns)
-            gv_tables[table].add_table(table, errors, sizes, keys, indexes, columns, True)
-            tables[table] = (table, errors, sizes, keys, indexes, columns)
+    print('Building graphs')
+    for table in db.get_tables():
+        columns = db.get_columns(table)
+        sizes = db.get_table_size(table)
+        keys = db.get_table_keys(table)
+        indexes = db.get_table_index(table)
+        errors = db.get_table_errors(table)
+        gv_map.add_table(table, errors, sizes, keys, indexes, columns)
+        gv_tables[table].add_table(table, errors, sizes, keys, indexes, columns, True)
+        tables[table] = (table, errors, sizes, keys, indexes, columns)
 
-        print('Adding constraints')
-        # Constraints
-        for table in db.get_tables():
-            for src, dst in db.get_foreign_keys(table):
-                gv_tables[table].add_table(*tables[dst[0]])
-                gv_tables[table].add_constraint(src, dst)
-                gv_tables[dst[0]].add_table(*tables[table])
-                gv_tables[dst[0]].add_constraint(src, dst)
-                gv_map.add_constraint(src, dst)
+    print('Adding constraints')
+    # Constraints
+    for table in db.get_tables():
+        for src, dst in db.get_foreign_keys(table):
+            gv_tables[table].add_table(*tables[dst[0]])
+            gv_tables[table].add_constraint(src, dst)
+            gv_tables[dst[0]].add_table(*tables[table])
+            gv_tables[dst[0]].add_constraint(src, dst)
+            gv_map.add_constraint(src, dst)
 
-        print('Adding missing constraints')
-        # Missing constraints
-        for table in db.get_tables():
-            for constraint in db.get_missing_constraints(table):
-                gv_tables[table].add_table(*tables[constraint[2]])
-                gv_tables[table].add_missing_constraint(*constraint)
-                gv_tables[constraint[2]].add_table(*tables[table])
-                gv_tables[constraint[2]].add_missing_constraint(*constraint)
-                gv_map.add_missing_constraint(*constraint)
+    print('Adding missing constraints')
+    # Missing constraints
+    for table in db.get_tables():
+        for constraint in db.get_missing_constraints(table):
+            gv_tables[table].add_table(*tables[constraint[2]])
+            gv_tables[table].add_missing_constraint(*constraint)
+            gv_tables[constraint[2]].add_table(*tables[table])
+            gv_tables[constraint[2]].add_missing_constraint(*constraint)
+            gv_map.add_missing_constraint(*constraint)
 
-        print('Adding inheritance')
-        # Inheritance link
-        for src, dst in db.get_inherited_tables():
-            gv_map.add_inherited(src, dst)
-            gv_tables[src].add_table(*tables[dst])
-            gv_tables[src].add_inherited(src, dst)
-            gv_tables[dst].add_table(*tables[src])
-            gv_tables[dst].add_inherited(src, dst)
+    print('Adding inheritance')
+    # Inheritance link
+    for src, dst in db.get_inherited_tables():
+        gv_map.add_inherited(src, dst)
+        gv_tables[src].add_table(*tables[dst])
+        gv_tables[src].add_inherited(src, dst)
+        gv_tables[dst].add_table(*tables[src])
+        gv_tables[dst].add_inherited(src, dst)
 
-        print('Adding duplicates')
-        for _tables, duplicate_type in db.get_duplicated_tables().items():
-            src, dst = _tables.split('/')
-            gv_map.add_duplicate(src, dst, duplicate_type)
-            gv_tables[src].add_table(*tables[dst])
-            gv_tables[src].add_duplicate(src, dst, duplicate_type)
-            gv_tables[dst].add_table(*tables[src])
-            gv_tables[dst].add_duplicate(src, dst, duplicate_type)
+    print('Adding duplicates')
+    for _tables, duplicate_type in db.get_duplicated_tables().items():
+        src, dst = _tables.split('/')
+        gv_map.add_duplicate(src, dst, duplicate_type)
+        gv_tables[src].add_table(*tables[dst])
+        gv_tables[src].add_duplicate(src, dst, duplicate_type)
+        gv_tables[dst].add_table(*tables[src])
+        gv_tables[dst].add_duplicate(src, dst, duplicate_type)
 
-        namespaces = db.get_namespaces().items()
-        if len(namespaces) != 1:
-            # Show namespaces only when there are more than one
-            for namespace, tables in namespaces:
-                gv_map.add_namespace(namespace, tables)
+    namespaces = db.get_namespaces().items()
+    if len(namespaces) != 1:
+        # Show namespaces only when there are more than one
+        for namespace, tables in namespaces:
+            gv_map.add_namespace(namespace, tables)
 
-        print('Building graphs images')
-        for gv in [gv_map] + list(gv_tables.values()):
-            gv.add_footer()
-            gv.close()
+    print('Building graphs images')
+    for gv in [gv_map] + list(gv_tables.values()):
+        gv.add_footer()
+        gv.close()
 
-            dot = DotFile(gv.basename.replace('.gv', '.png'))
-            dot.render(gv.filename)
+        dot = DotFile(gv.basename.replace('.gv', '.png'))
+        dot.render(gv.filename)
 
-            table_html = TableFile(gv.basename.replace('.gv', '.html'))
-            table_html.render()
+        table_html = TableFile(gv.basename.replace('.gv', '.html'))
+        table_html.render()
 
     # Generate HTML files
     html_file = IndexFile('index.html')

--- 
+++ 
@@ -24,10 +24,3 @@
         if '\n' not in buf:
             buf += '\n'
         self.fd.write(buf)
-
-    def exists(self, filename=None):
-        filename = filename or self.filename
-        exists = os.path.exists(filename)
-        if exists:
-            print("Warning: file %s already exists. Remove it first to rebuild it." % filename)
-        return exists