feat: Oracle - make connection lazy, add closing methods and refactor tests (#3665)

Author: anakin87

integrations/oracle/src/haystack_integrations/components/retrievers/oracle/embedding_retriever.py

@@ -84,6 +84,12 @@ async def run_async(
         )
         return {"documents": docs}
 
+    def close(self) -> None:
+        """
+        Release the synchronous resources of the underlying Document Store.
+        """
+        self.document_store.close()
+
     def to_dict(self) -> dict[str, Any]:
         """
         Serializes the component to a dictionary.

integrations/oracle/src/haystack_integrations/components/retrievers/oracle/keyword_retriever.py

@@ -82,6 +82,12 @@ async def run_async(
         )
         return {"documents": docs}
 
+    def close(self) -> None:
+        """
+        Release the synchronous resources of the underlying Document Store.
+        """
+        self.document_store.close()
+
     def to_dict(self) -> dict[str, Any]:
         """
         Serializes the component to a dictionary.

integrations/oracle/src/haystack_integrations/document_stores/oracle/document_store.py

@@ -8,6 +8,7 @@
 import logging
 import re
 import threading
+from contextlib import suppress
 from dataclasses import dataclass
 from typing import Any, Literal
 
@@ -177,11 +178,7 @@ def __init__(
 
         self._pool: oracledb.ConnectionPool | None = None
         self._pool_lock = threading.Lock()
-
-        if create_table_if_not_exists:
-            self._ensure_table()
-        if create_index:
-            self.create_hnsw_index()
+        self._setup_done = False
 
     def _get_pool(self) -> oracledb.ConnectionPool:
         if self._pool is not None:
@@ -212,14 +209,33 @@ def _get_pool(self) -> oracledb.ConnectionPool:
         return self._pool
 
     def _get_connection(self) -> oracledb.Connection:
+        self._ensure_setup()
         return self._get_pool().acquire()
 
-    def __del__(self) -> None:
+    def _ensure_setup(self) -> None:
+        """
+        Create the backing table and optional HNSW index once, on first use if needed.
+        """
+        if self._setup_done:
+            return
+        self._setup_done = True
+        try:
+            if self.create_table_if_not_exists:
+                self._ensure_table()
+            if self.create_index:
+                self.create_hnsw_index()
+        except Exception:
+            self._setup_done = False
+            raise
+
+    def close(self) -> None:
+        """
+        Release the associated synchronous resources.
+        """
         if self._pool is not None:
-            try:
+            with suppress(Exception):
                 self._pool.close()
-            except Exception:
-                logger.warning("Failed to close Oracle connection pool during cleanup.", exc_info=True)
+            self._pool = None
 
     def _ensure_table(self) -> None:
         sql = f"""

integrations/oracle/tests/conftest.py

@@ -16,36 +16,41 @@
 _DSN = "localhost:1521/freepdb1"
 
 
-def _make_store(table: str, embedding_dim: int) -> OracleDocumentStore:
-    return OracleDocumentStore(
-        connection_config=OracleConnectionConfig(
-            user=Secret.from_token(_USER),
-            password=Secret.from_token(_PASSWORD),
-            dsn=Secret.from_token(_DSN),
-        ),
-        table_name=table,
-        embedding_dim=embedding_dim,
-        distance_metric="COSINE",
-        create_table_if_not_exists=True,
-    )
+@pytest.fixture
+def make_store():
+    """Factory for a real OracleDocumentStore. Uses token secrets, so instances are not serialization-safe."""
+
+    def _make(table: str, embedding_dim: int = 4, *, create_table_if_not_exists: bool = True) -> OracleDocumentStore:
+        return OracleDocumentStore(
+            connection_config=OracleConnectionConfig(
+                user=Secret.from_token(_USER),
+                password=Secret.from_token(_PASSWORD),
+                dsn=Secret.from_token(_DSN),
+            ),
+            table_name=table,
+            embedding_dim=embedding_dim,
+            create_table_if_not_exists=create_table_if_not_exists,
+        )
+
+    return _make
 
 
 @pytest.fixture
-def document_store():
+def document_store(make_store):
     """768-dim store required by the mixin's filterable_docs fixture."""
     table = f"hs_sync_{uuid.uuid4().hex[:8]}"
-    s = _make_store(table, embedding_dim=768)
+    s = make_store(table, 768)
     yield s
     with s._get_connection() as conn, conn.cursor() as cur:
         cur.execute(f"DROP TABLE {table} PURGE")
         conn.commit()
 
 
 @pytest.fixture
-def embedding_store():
+def embedding_store(make_store):
     """4-dim store for embedding-retrieval, HNSW, and async tests."""
     table = f"hs_emb_{uuid.uuid4().hex[:8]}"
-    s = _make_store(table, embedding_dim=4)
+    s = make_store(table)
     yield s
     with s._get_connection() as conn, conn.cursor() as cur:
         cur.execute(f"DROP TABLE {table} PURGE")