Matching guests works nicely

src/alpine_bits_python/db.py

@@ -187,6 +187,33 @@ class ResilientAsyncSession:
         raise last_error
 
 
+class SessionMaker:
+    """Factory for creating independent AsyncSession instances.
+
+    This class enables concurrent processing by allowing each task to create
+    and manage its own database session. Useful for processing large datasets
+    where concurrent execution is desired but each concurrent task needs its own
+    database transaction context.
+    """
+
+    def __init__(self, async_sessionmaker_: async_sessionmaker[AsyncSession]):
+        """Initialize the SessionMaker.
+
+        Args:
+            async_sessionmaker_: SQLAlchemy async_sessionmaker factory
+        """
+        self.async_sessionmaker = async_sessionmaker_
+
+    async def create_session(self) -> AsyncSession:
+        """Create a new independent AsyncSession.
+
+        Returns:
+            A new AsyncSession instance ready for use. Caller is responsible
+            for managing the session lifecycle (closing when done).
+        """
+        return self.async_sessionmaker()
+
+
 async def get_resilient_session(
     resilient_session: "ResilientAsyncSession",
 ) -> AsyncGenerator[AsyncSession, None]:
@@ -416,9 +443,10 @@ class RoomReservation(Base):
         Integer, ForeignKey("conversions.id"), nullable=False, index=True
     )
 
-    # Unique identifier for this room reservation (for upserts)
+    # Identifier for this room reservation (for upserts)
     # Composite: pms_reservation_id + room_number
-    pms_hotel_reservation_id = Column(String, unique=True, index=True)
+    # Note: Not globally unique - same room number can exist across different hotels
+    pms_hotel_reservation_id = Column(String, index=True)
 
     # Room reservation details
     arrival_date = Column(Date, index=True)  # arrival attribute