database/postgres.py

```python
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker
from models.escalation_models import EscalationTicket, TicketResponse
import os

engine = create_async_engine(os.getenv("POSTGRES_URL"))
AsyncSessionLocal = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)

class PostgresService:
    async def create_ticket(self, ticket: EscalationTicket) -> int:
        async with AsyncSessionLocal() as session:
            # Implementation for ticket creation
            pass
    
    async def get_tickets(self, status: str = None) -> list[TicketResponse]:
        async with AsyncSessionLocal() as session:
            # Implementation for ticket retrieval
            pass
```