support sets for pyarrow

dlt/common/libs/pyarrow.py

@@ -620,15 +620,15 @@ def row_tuples_to_arrow(
             )
             float_array = pa.array(columnar_known_types[field.name], type=pa.float64())
             columnar_known_types[field.name] = float_array.cast(field.type, safe=False)
-        if issubclass(py_type, (dict, list)):
+        if issubclass(py_type, (dict, list, set)):
             logger.warning(
                 f"Field {field.name} was reflected as JSON type and needs to be serialized back to"
                 " string to be placed in arrow table. This will slow data extraction down. You"
                 " should cast JSON field to STRING in your database system ie. by creating and"
                 " extracting an SQL VIEW that selects with cast."
             )
             json_str_array = pa.array(
-                [None if s is None else json.dumps(s) for s in columnar_known_types[field.name]]
+                [None if s is None else json.dumps(s) if not issubclass(type(s), set) else json.dumps(list(s)) for s in columnar_known_types[field.name]]
             )
             columnar_known_types[field.name] = json_str_array
 

docs/website/docs/general-usage/credentials/index.md

@@ -5,13 +5,13 @@ keywords: [credentials, secrets.toml, secrets, config, configuration, environmen
 ---
 import DocCardList from '@theme/DocCardList';
 
-`dlt` pipelines usually require configurations and credentials. These can be set up in [various ways](./setup):
+`dlt` pipelines usually require configurations and credentials. These can be set up in [various ways](setup):
 
 1. Environment variables
 2. Configuration files (`secrets.toml` and `config.toml`)
 3. Key managers and vaults
 
-`dlt` automatically extracts configuration settings and secrets based on flexible [naming conventions](./setup/#naming-convention). It then [injects](./advanced/#injection-mechanism) these values where needed in code.
+`dlt` automatically extracts configuration settings and secrets based on flexible [naming conventions](setup/#naming-convention). It then [injects](advanced/#injection-mechanism) these values where needed in code.
 
 # Learn details about