Add datasource type exclusion from schema refresh

- Add SCHEMAS_REFRESH_EXCLUDED_TYPES setting with default 'results,python'
- Add type-based exclusion check in refresh_schemas()
- Prevents unnecessary errors for datasources without schema support

Author: snickerjp

redash/settings/__init__.py

@@ -51,6 +51,9 @@
 
 SCHEMAS_REFRESH_SCHEDULE = int(os.environ.get("REDASH_SCHEMAS_REFRESH_SCHEDULE", 30))
 SCHEMAS_REFRESH_TIMEOUT = int(os.environ.get("REDASH_SCHEMAS_REFRESH_TIMEOUT", 300))
+SCHEMAS_REFRESH_EXCLUDED_TYPES = set_from_string(
+    os.environ.get("REDASH_SCHEMAS_REFRESH_EXCLUDED_TYPES", "results,python")
+)
 
 AUTH_TYPE = os.environ.get("REDASH_AUTH_TYPE", "api_key")
 INVITATION_TOKEN_MAX_AGE = int(os.environ.get("REDASH_INVITATION_TOKEN_MAX_AGE", 60 * 60 * 24 * 7))

redash/tasks/queries/maintenance.py

@@ -205,6 +205,8 @@ def refresh_schemas():
             )
         elif ds.id in blacklist:
             logger.info("task=refresh_schema state=skip ds_id=%s reason=blacklist", ds.id)
+        elif ds.type in settings.SCHEMAS_REFRESH_EXCLUDED_TYPES:
+            logger.info("task=refresh_schema state=skip ds_id=%s reason=type_excluded", ds.id)
         elif ds.org.is_disabled:
             logger.info("task=refresh_schema state=skip ds_id=%s reason=org_disabled", ds.id)
         else: