limit tables/views returned if schema is not provided (#7358)

* limit tables/views returned if schema is not provided

* fix typo

* improve code performance

* handle the case when table name or view name does not present a schema

superset/models/core.py

@@ -748,6 +748,10 @@ class Database(Model, AuditMixinNullable, ImportMixin):
     def table_cache_timeout(self):
         return self.metadata_cache_timeout.get('table_cache_timeout')
 
+    @property
+    def default_schemas(self):
+        return self.get_extra().get('default_schemas', [])
+
     @classmethod
     def get_password_masked_url_from_uri(cls, uri):
         url = make_url(uri)

superset/views/core.py

@@ -1513,6 +1513,16 @@ class Superset(BaseSupersetView):
             table_names = [tn for tn in table_names if substr in tn]
             view_names = [vn for vn in view_names if substr in vn]
 
+        if not schema and database.default_schemas:
+            def get_schema(tbl_or_view_name):
+                return tbl_or_view_name.split('.')[0] if '.' in tbl_or_view_name else None
+
+            user_schema = g.user.email.split('@')[0]
+            valid_schemas = set(database.default_schemas + [user_schema])
+
+            table_names = [tn for tn in table_names if get_schema(tn) in valid_schemas]
+            view_names = [vn for vn in view_names if get_schema(vn) in valid_schemas]
+
         max_items = config.get('MAX_TABLE_NAMES') or len(table_names)
         total_items = len(table_names) + len(view_names)
         max_tables = len(table_names)