feast-dev · ntkathole · Jul 30, 2026 · Jul 24, 2026 · Jul 27, 2026 · Jul 30, 2026
@@ -6,7 +6,7 @@
 from pathlib import Path
 from typing import Any, Callable, Dict, List, Optional, Union, cast
 
-from pydantic import StrictInt, StrictStr
+from pydantic import StrictInt, StrictStr, field_validator
 from sqlalchemy import (  # type: ignore
     BigInteger,
     Column,
@@ -306,6 +306,15 @@ class SqlRegistryConfig(RegistryConfig):
     thread_pool_executor_worker_count: StrictInt = 0
     """ int: Number of worker threads to use for asynchronous caching in SQL Registry. If set to 0, it doesn't use ThreadPoolExecutor. """
 
+    @field_validator("read_path")
+    def validate_read_path(cls, read_path: Optional[str]) -> Optional[str]:
+        # Mirror `RegistryConfig.validate_path`: a bare `postgresql://` read_path
+        # must be rewritten to the psycopg3 driver too, otherwise it silently
+        # falls back to psycopg2 while `path` uses psycopg3.
+        if read_path is not None:
+            return cls._normalize_postgres_scheme(read_path, "read_path")
+        return read_path
+
 
 class SqlRegistry(CachingRegistry):
     def __init__(

@@ -205,19 +205,33 @@ class RegistryConfig(FeastBaseModel):
     mcp: Optional[McpRegistryConfig] = None
     """ McpRegistryConfig: MCP (Model Context Protocol) configuration for the registry REST server. """
 
+    @staticmethod
+    def _normalize_postgres_scheme(value: str, field_name: str) -> str:
+        """Rewrite a bare ``postgresql://`` URL to the psycopg3 driver, with a warning.
+
+        SQLAlchemy resolves a bare ``postgresql://`` to the psycopg2 driver, while
+        feast standardizes on psycopg3 (``postgresql+psycopg``). Pass an explicit
+        ``postgresql+psycopg2`` to keep psycopg2. Shared by the ``path`` and
+        ``read_path`` validators so both endpoints normalize identically.
+        """
+        if value.startswith("postgresql://"):
+            _logger.warning(
+                f"The `{field_name}` of the `RegistryConfig` starts with a plain "
+                "`postgresql` string. We are updating this to `postgresql+psycopg` "
+                "to ensure that the `psycopg3` driver is used by `sqlalchemy`. If "
+                f"you want to use `psycopg2` pass `postgresql+psycopg2` explicitly "
+                f"to `{field_name}`. To silence this warning, pass `postgresql+psycopg` "
+                f"explicitly to `{field_name}`."
+            )
+            # Rewrite only the leading scheme, not any later occurrence (e.g.
+            # inside credentials or a query string).
+            return "postgresql+psycopg://" + value[len("postgresql://") :]
+        return value
+
     @field_validator("path")
     def validate_path(cls, path: str, values: ValidationInfo) -> str:
         if values.data.get("registry_type") == "sql":
-            if path.startswith("postgresql://"):
-                _logger.warning(
-                    "The `path` of the `RegistryConfig` starts with a plain "
-                    "`postgresql` string. We are updating this to `postgresql+psycopg` "
-                    "to ensure that the `psycopg3` driver is used by `sqlalchemy`. If "
-                    "you want to use `psycopg2` pass `postgresql+psycopg2` explicitely "
-                    "to `path`. To silence this warning, pass `postgresql+psycopg` "
-                    "explicitely to `path`."
-                )
-                return path.replace("postgresql://", "postgresql+psycopg://")
+            return cls._normalize_postgres_scheme(path, "path")
         return path
 
 

@@ -65,6 +65,72 @@ def shared_sqlite_db_path():
     yield path
 
 
+def test_read_path_normalizes_bare_postgresql_scheme(caplog):
+    """A bare `postgresql://` read_path is rewritten to the psycopg3 driver, the
+    same way `path` is, and logs a migration warning. Without this, read_path
+    silently falls back to psycopg2 while path uses psycopg3."""
+    with caplog.at_level(logging.WARNING):
+        config = SqlRegistryConfig(
+            registry_type="sql",
+            path="postgresql://localhost:5432/db",
+            read_path="postgresql://localhost:5432/replica",
+        )
+    assert config.path == "postgresql+psycopg://localhost:5432/db"
+    assert config.read_path == "postgresql+psycopg://localhost:5432/replica"
+    # The migration warning names the read_path field specifically.
+    assert "`read_path` of the `RegistryConfig`" in caplog.text
+
+
+def test_read_path_normalized_when_registry_type_defaulted():
+    """read_path normalization must still fire when registry_type is left to its
+    default ('sql') rather than passed explicitly — the common real-world config."""
+    config = SqlRegistryConfig(
+        path="postgresql://localhost/db",
+        read_path="postgresql://localhost/replica",
+    )
+    assert config.registry_type == "sql"
+    assert config.read_path == "postgresql+psycopg://localhost/replica"
+
+
+@pytest.mark.parametrize(
+    "read_path",
+    [
+        "postgresql+psycopg2://localhost/replica",  # explicit psycopg2 preserved
+        "postgresql+psycopg://localhost/replica",  # already psycopg3
+        "mysql://localhost/replica",  # non-postgres left untouched
+    ],
+)
+def test_read_path_leaves_explicit_scheme_untouched(read_path):
+    config = SqlRegistryConfig(
+        registry_type="sql",
+        path="sqlite:///unused.db",
+        read_path=read_path,
+    )
+    assert config.read_path == read_path
+
+
+def test_read_path_none_stays_none():
+    config = SqlRegistryConfig(registry_type="sql", path="sqlite:///unused.db")
+    assert config.read_path is None
+
+
+@pytest.mark.parametrize("field_name", ["path", "read_path"])
+def test_postgres_normalization_only_rewrites_leading_scheme(field_name):
+    raw_url = "postgresql://localhost/db?target=postgresql://replica"
+    config_values = {
+        "registry_type": "sql",
+        "path": "sqlite:///unused.db",
+    }
+    config_values[field_name] = raw_url
+
+    config = SqlRegistryConfig(**config_values)
+
+    assert (
+        getattr(config, field_name)
+        == "postgresql+psycopg://localhost/db?target=postgresql://replica"
+    )
+
+
 def test_proto_columns_use_longblob_on_mysql():
     """On MySQL and MariaDB, serialized-proto columns must compile to LONGBLOB.